1. Lesson 1
The Alpha and the Omega (Part 1)
Amen! Hallelujah! – A Study of the Book of Revelation
By Dale Wells
Text: Rev 1.1-8; Rev 22.8-12
2. Revelation is a book to be
understood
Rev 1:1-3 WEB This is
the Revelation of Jesus
Christ …
Apocalypsis – an
“unveiling”, “revealing”,
or “disclosure”
The book is not a
“mystery”
(mysterion), but a
“revelation”
3. "Blessed is he who reads"
Rev 1:3 WEB Blessed
is he who reads and
those who hear the
words of the prophecy,
and keep the things that
are written in it...
Ho anaginooskon – “the
one reading aloud”
Apparent in blessing
“those who hear”
Envisions one reading to
a congregation
4. “Blessed are those who hear”
Akouoo with a genitive
noun meant “hear”
With the accusative, as
here, it meant
“understand”
Jesus intended the
message to be
understood
5. “Blessed are … those who … keep
the things … in it”
Terountes means “observe”, or “obey”
God intended people to “understand” and “obey”
the book, so he must have written one they could
understand and were capable of obeying!
Why is the book misunderstood?
People misunderstand the book because of faulty
assumptions they bring to the text, not because of
what the text, itself, says
6. Popular approaches to Revelation
Some see it as a “summary of history”
They see the Catholic Church, Reformation, Luther & Calvin
Philip Melanchthon, Luther’s contemporary, took this approach
Recent authors are Albert Barnes and John Hinds
Each reapplies history to put himself in the last days
Some believe it only deals with the end of time
Authors since 1948 think we are in the last moments of time
Each rewrites when time proves him wrong
Something is wrong with an approach that rewrites
interpretation every time history disproves it
7. The time frame is set by two phrases
Dei genesthai en tachei - “which must happen soon”
Rev 1:1 WEB … the Revelation of Jesus Christ, which God
gave him to show … the things which must happen soon...
Rev 22:6 WEB He said to me, “… The Lord God … sent his
angel to show … the things which must happen soon.”
Some believe that en tachei means “certainly”
Not so! Tacheoo always means “quickly”.
Act 22:17-18 WEB “… while I prayed … I fell into a trance, and
saw him saying to me, 'Hurry and get out of Jerusalem quickly,”
Gal 1:6-7 WEB I marvel that you are so quickly deserting him
who called you in the grace of Christ to a different gospel …
2Ti 4:9 WEB Be diligent to come to me soon...
Readers of Revelation understood that the fulfillment
would be soon - from their point of view, not ours!
8. The time is at hand
Ho gar kairos engus – “for the time is at hand”
Engus means “in hand” or “within reach”
The use of “the time is at hand”
Rev 1:3 WEB Blessed is he who reads … those who hear …
and keep the things … written in it, for the time is at hand.
Rev 22:10 WEB He said to me, “Don't seal up the words of
the prophecy of this book, for the time is at hand.
This same expression is used elsewhere
Mar 1:14-15 WEB … Jesus came … saying, “The time is
fulfilled, and the Kingdom of God is at hand! …”
Rom 10:8-9 WEB The word is near you...
Phi 4:5 WEB The Lord is at hand.
No text uses engus of something far away
9. Reasons for interpreting the book in
light of its time:
It was a “revelation” to its readers, not a “mystery”
It was intended to be read, understood and acted on
Its time of fulfillment was close at hand
Picture yourself as a Christian in Pergamum
Antipas has been executed for his faith. You may be next!
A messenger comes with John's letter.
Do you want to know what to expect in 2000 years? No!
You want to know if you’re going to be alive tomorrow! If not,
what then? Was it worth it for Antipas – or for you?
You don’t care about 21st Century writers. You want to know
what’s going to happen to you and what God is doing about it!
A message to early Christians about their concerns!
10. Keys to understanding Revelation
All literature is not read alike
Elizabeth Barrett Browning vs. Edgar Allen Poe
William Shakespeare vs. Stephen King
Newspaper vs. poetry; biography vs. prophecy;
history vs. a math textbook
They are not interpreted the same way
Revelation is written in apocalyptic style
Makes heavy use of symbols
Imagery that is not intended to be taken literally
11. What if I told you that yesterday, I
saw a vision
I saw what looked like a living creature
It had four legs, but it stood up on two, like a man. It had a
prominent nose. It was brown with long ears
I saw another living creature
It looked like a bird without wings. It was blue and had two
legs with three toes on each foot
The first creature sat astride a red cylinder
The first creature sped toward the second creature
The second stepped aside as the first sped past
Who are the two creatures?
12. Read Revelation the way you watch
animations – use your imagination
7-headed dragon, 7-
headed beast, lamb
with 7 horns and eyes,
prostitute on a beast
Don’t let details distract
you from the picture
Let the picture grab
your imagination and
you will understand it
Revelation uses
symbols extensively
Some are self-evident
13. Consider John's description of one
like a son of man in Rev 1:13-18
Robe and gold sash
Hair like white wool
Eyes like a flame of fire
Feet like brass
Sword out of his mouth
Face like the sun
I am the first and the
last, and the Living one
I was dead, and … I am
alive forevermore
This is clearly Jesus.
14. Look at the description of the Lamb
of God in Rev 5:5-6
Lion of Judah
Root of David
He who opens the book
and its seven seals
Lamb standing, as
though it had been slain
It cannot be anyone but
Jesus
15. Consider the vignette about two
witnesses in Rev 11:6
Shut up the sky that
it may not rain
Comes from Elijah
Turn water into
blood and strike the
earth with plagues
Come from Moses
16. A radiant woman gives birth to a
unique child in Rev 12:1-5
Clothed with the sun
Moon under her feet
Crown of twelve stars
Pregnant and in labor
Gives birth to a son who
is to rule the nations
with a rod of iron
John expects his
readers to identify the
woman as Mary, and
her child as Jesus
17. A conquering king rides in on a white
horse in Rev 19:11-16
Faithful and True
Eyes are a flame of fire
Many crowns
Covered with blood
“The Word of God”
Sword out of his mouth
Rules with a rod of iron
King of Kings and Lord
of Lords
No doubt this is Jesus
18. The text explains the less obvious
symbols
What are the stars and
lampstands?
Rev 1:20 WEB … The
seven stars are the
angels of the seven
assemblies. The seven
lampstands are seven
assemblies.
The lampstands are
churches and the stars
are their messengers
19. What about the dragon out to devour
the child?
Rev 12:9 WEB The
great dragon …, the old
serpent, he who is
called the devil and
Satan ...
In the Apocalypse, the
dragon is Satan
20. John sees a prostitute riding on a
seven-headed beast in Rev 17
Rev 17:18 WEB The
woman … is the great
city which reigns over
the kings of the earth.”
Rev 17:9-11 WEB The
seven heads are seven
mountains, on which
the woman sits. They
are also seven kings …
Rome sat on 7 hills and
ruled the world – the
prostitute is Rome
21. A puzzle to solve, not a mystery to
ignore
Start with what you
know
Lamb is Jesus
Dragon is Satan
Prostitute is Rome
Heads are emperors
Start there and the
picture comes together!
23. The symbolism of numbers
Apocalyptic literature
used numbers
symbolically
Four numerals are
oppositional pairs.
7 stands opposed to 3 ½
12 stands opposed to 6
Others are not paired
1/3, 2, 4, 10, 1,000
Oppositional pairs are a
feature of Revelation
24. There are two lambs
The Lamb of God
Rev 5:6 WEB I saw in
the midst of the throne …
a Lamb standing, as
though it had been slain
A lamb that speaks with
the voice of a dragon
Rev 13:11 WEB I saw
another … He had two
horns like a lamb, and he
spoke like a dragon.
25. Two oppositional women
The prostitute
Rev 19:1-2 NIV … God
… has condemned the
great prostitute …
The bride of the Lamb
Rev 19:7 NIV Let us
rejoice and be glad and
give him glory! For the
wedding of the Lamb has
come, and his bride has
made herself ready.
26. Two who claim dominion
God on the throne
Rev 4:2 WEB …
Behold, there was a
throne … and one sitting
on the throne
Dragon who attempts to
invade heaven
Rev 12:7 WEB …
Michael and his angels
made war on the dragon.
The dragon and his
angels made war.
27. Two marks on people’s foreheads
The seal of God
Rev 7:3 WEB Don't
harm the earth… until we
have sealed the
bondservants of our God
on their foreheads!
The mark of the beast
Rev 13:16-17 WEB He
causes all … to be given
marks on their right
hands, or on their
foreheads …
28. Kings of the earth and the King of
Kings
Rev 17:12 WEB The
ten horns … are ten
kings …
Rev 19:16 WEB He
has … a name written,
“KING OF KINGS, AND
LORD OF LORDS.”
There are other
opposites, but this gives
you the idea
Some numbers are also
in oppositional pairs
29. Seven symbolizes God's completed
work
7 occurs …
more in Revelation than
the rest of the NT
more in Revelation than
in any OT book
7 symbolizes God
finishing his work
Gen 2:1-3 WEB … On
the seventh day God
finished his work … and
he rested on the seventh
day ...
30. Revelation begins with a letter to 7
churches.
Rev 1:4 WEB John, to
the seven assemblies ...
Rev 1:11 WEB ... “What
you see, write in a book
and send to the seven
assemblies …”
Rev 1:20 WEB ... The
seven lampstands are
seven assemblies.
Ekklesiai is “churches”
in other translations
31. The first vision features two sevens
The son of man is
among 7 lampstands
Rev 1:20 WEB ... The
seven lampstands are
seven assemblies.
He is holding 7 stars
Rev 1:20 WEB ... The
seven stars are the
angels of the seven
assemblies...
32. Before God's throne were 7 lamps
Rev 4:5 WEB ... There
were seven lamps of
fire burning before his
throne, which are the
seven Spirits of God.
These are seen
elsewhere
Rev 1:4 WEB ... Grace to
you and peace ... from
the seven Spirits who are
before his throne
33. A 7-sealed scroll was opened by a
Lamb with 7 horns and 7 eyes
Rev 5:1-6 WEB I saw,
in the right hand of him
who sat on the throne, a
book written inside and
outside, sealed shut
with seven seals … (6)
I saw … a Lamb
standing, as though it
had been slain, having
seven horns, and seven
eyes …
34. God's judgments were announced by
7 angels with 7 trumpets.
Rev 8:2-6 WEB I saw
the seven angels who
stand before God, and
seven trumpets were
given to them … (6)
The seven angels who
had the seven trumpets
prepared themselves to
sound.
35. 7 angels administer God's judgments
Rev 15:1 WEB I saw …
seven angels having
the seven last plagues,
for in them God's wrath
is finished.
Rev 15:6-8 WEB …
One of the four living
creatures gave to the
seven angels seven
golden bowls full of the
wrath of God...
36. 7 bowls of wrath were poured out on
the earth.
Rev 16:1 WEB I heard
a loud voice out of the
temple, saying to the
seven angels, “Go and
pour out the seven
bowls of the wrath of
God on the earth!”
37. 3½ depicts Satan's attempt to thwart
God's purpose
3 ½ is opposed to 7
7 is God doing his will.
3½ is a time of suffering
Daniel envisioned a 3 ½
year oppression
Dan 7:25 WEB He shall
speak … against the
Most High, and … the
saints … be given into
his hand until a time and
times and half a time.
A year (“time”) + 2 years
(“times”) + 6 months
(“half a time”).
38. A time of oppression and provision
Drought during the
reign of Ahab
Jam 5:17 WEB Elijah …
prayed … that it might
not rain, and it didn't rain
on the earth for three
years and six months.
God provided for Elijah
1Ki 17:3-6 WEB … (6)
The ravens brought him
bread and flesh in the
morning, and bread and
flesh in the evening; and
he drank of the brook.
39. The picture comes from military
sieges
Measured in months
Roman army surrounded
a city, cutting off supplies
Built siegeworks and
starved the city
Jewish-Roman War
Began in 66 AD
Jerusalem fell 42 months
later in 70 AD
A time when Satan tries
to stop God’s work, but
God is still in control!
40. 3½ years in Revelation 11
Gentiles besiege God’s
city for 42 months
Rev 11:1-2 … They will
tread the holy city under
foot for forty-two months.
God's witnesses preach
for the same 1260 days
Rev 11:3 … my two
witnesses … will
prophesy one thousand
two hundred sixty days
41. 3½ years as 1260 days and “a time,
times, and half a time”
God cares for the
woman for 1260 days
Rev 12:6
Satan tries to get at the
woman for a time, times
and half a time
Rev 12:13-14
He can’t get to
her, because God is
protecting her
The outcome is always
the same – God wins!
42. Twelve symbolizes God's people
12 and multiples (24,
12,000, 144,000) is the
second most prominent
number in Revelation
In Rev 4:4, 24 elders sit
on thrones
24 elders are God’s
people in two covenants
12 patriarchs (Old
Testament)
12 apostles (New
Testament)
43. In Revelation 7 there are 144,000
people sealed
Rev 7:4 WEB … one
hundred forty-four
thousand, sealed out of
every tribe of the
children of Israel
These are people with
God’s seal of approval
on their foreheads
12,000 from each of the
12 tribes of Israel
The number is not literal
44. The radiant woman in Rev 12 wears
a crown of twelve stars
Rev 12:1 WEB … a
woman … and on her
head a crown of twelve
stars
We saw this woman
earlier as an idealized
picture of Mary
The 12 stars represent
God’s people – her
crowning glory
45. 12 dominates the description of the
holy city in Rev 21:10-17
12 gates
12 angels
Names of 12 tribes
12 foundations
12 names of the 12
Apostles
12,000 stadia
Wall is 144 cubits
46. This is the city where God’s people
live!
It is a cube 12,000
stadia on each side,
with 12 gates, having
walls 144 cubits thick.
The city has plenty of
access (gates)
room (dimensions)
security (angels at the
gates)
protection (walls)
47. 6 symbolizes rebellion against God
It depicts man’s attempt
to dispense with God
Contrast of 6 and 12
12 is God’s faithful
people protected by him
6 is man in rebellion
against God
Like Satan’s attempts to
stop God (3 ½), man’s
rebellion always fails
48. The most infamous use of 6 is the
number of the beast in Rev 13:18
Rev 13:18 WEB … His
number is six hundred
sixty-six.
Rebellion compounded
Man’s attempt to usurp
God’s throne
666 is a gematria
The number concealed a
name the readers knew,
but history quickly forgot
Irenaeus (2nd Century)
suggested names, but
couldn’t determine the
name behind the number
49. Ancient alphabets were not like our
modern alphabets
Hebrew and Greek had
alphabets composed of
characters that served a
dual purpose as letters
and numbers
Thus “a” could either
serve as a letter, or it
could be the numeral
“1”, “b” could be used
as the numeral “2”, etc.
50. Ancient writers engaged in
“gematria” (Greek isopsephia)
They added the letter values and the sum was the
"number" of the name
The sum represented the name when they wanted to reveal
the identity to some, but conceal it from others
This is important to understanding “666” in Rev 13:18
Ancient examples of gematria
Graffiti in Pompeii: “I love her whose number is 545.” Only
the couple would know about whom he was writing.
A Roman inscription describes Gaius as holy and good
Gaios = 3 + 1 + 10 + 70 + 200 = 284
(Ha)gios = 1 + 3 + 10 + 70 + 200 = 284
Aga(th)os =1 + 3 + 1 + 9 + 70 + 200 = 284
The words are gematrically interchangeable
51. Possible names that make sense in
light of the historical setting
Lateinos = “Latin” (e.g. Rome, the city or the empire)
= 30+1+300+5+10+50+70+200 = 666
Teitan = “Titus” (common name of the Flavian
Emperors. Vespasian was emperor when Revelation
was written. Titus ascended shortly thereafter.
Domitian began the empire-wide persecution of
Christians.) = 300+5+10+300+1+50 = 666
Kaisarsebaston = “Caesar Augustus” (“worshipful
Caesar”). The imperial name =
20+1+10+200+1+100+200+5+2+1+6+70+50 = 666
(Note: this requires using the obsolete letter stigma (= 6) in
the place of the letters sigma (= 200) and tau (= 300). Recall
the book was intended to be read aloud. The hearers would
be used to associating the “st” sound with the value of 6.)
52. 1/3 symbolizes God’s restraint in
judgment in Rev 8:6-12
1/3 earth burnt up
1/3 trees burnt up
1/3 sea became blood
1/3 sea creatures died
1/3 ships destroyed
1/3 rivers struck by star
1/3 waters became
wormwood
1/3 sun, moon and stars
darkened
53. Old Testament roots in Ezekiel 5
where he was told to shave his head
Eze 5:1-2 WEB … (2)
A third part you shall
burn … in the … city …
take a third part, and
strike with the sword …
a third part you shall
scatter to the wind ….
Eze 5:12 WEB A third
… shall die … and a
third … shall fall by the
sword … and a third …
I will scatter to … the
winds, and … draw … a
sword after them
54. Two symbolizes testimony
Emissaries sent in pairs
Mar 6:7 WEB He …
began to send them out
two by two …
Mat 11:2-3 WEB … John
… sent two ... disciples
Jewish law of evidence
required two witnesses
Deu 19:15 WEB One
witness shall not rise up
against a man … at the
mouth of two witnesses,
or … three … shall a
matter be established.
55. The only significant usage of two is in
Rev 11:3-11
2 witnesses
prophesy 1260 days
They are 2 olive
trees
They are also 2
lampstands, standing
before the Lord
They are also 2
prophets
56. The image comes from Zechariah 4
Zec 4:2-3 WEB … “I
have seen, and
behold, a lampstand all
of gold, … (3) and two
olive trees by it…”
Zec 4:11-14 WEB Then
I asked him, “What are
these two olive trees …
(14) Then he
said, “These are the two
anointed ones who
stand by the Lord of the
whole earth.”
57. The two represent the testimony of
the Law and Prophets
Moses and Elijah at
Transfiguration
Mat 17:1-3 WEB … (2)
He was transfigured
before them. His face
shone like the sun, and
his garments became as
white as the light. (3)
Behold, Moses and Elijah
appeared to them talking
with him.
In Rev 11 they are sent
to proclaim God's word
58. Four symbolizes the entire earth and
universe
Symbol of 4 derives
from 4 compass points,
4 wind directions and 4
seasons
Babylonian mythology:
4 signs of the Zodiac,
Taurus, Leo, Scorpio
and Aquarius, powerful
figures supporting
heaven by 4 corners, or
as the beasts of burden
of the 4-wheeled
heavenly chariot
59. Ezekiel 1 described 4 creatures of
God's heavenly entourage
4 living creatures
Each had 4 faces:
man, lion, ox and eagle
Each had 4 wings
Eze 1:4-28 WEB This
was the appearance of
the likeness of the glory
of Yahweh.
60. John saw 4 creatures around God's
throne worshiping him in Rev 4:6-8
Rev 4:6-8 WEB …
around the throne were
four living creatures ...
(7) The first … like a
lion, … the second …
like a calf, and the third
… had a face like a
man, and the fourth …
like a flying eagle. (8)
… They have no rest
day and night, saying,
“Holy, holy, holy is the
Lord God, the Almighty
…”
61. The 4 creatures worship the Lamb in
Rev 5:6-14
Rev 5:6-14 WEB … (8)
… the four living
creatures … fell down
before the Lamb … (9)
… saying, “You are
worthy … (11) … I
heard … a voice of
many angels … (12)
saying … “Worthy is the
Lamb …” (14) The four
living creatures said,
“Amen!”
62. Zechariah 6 has 4 chariots depicting
God's omnipresence & omniscience
4 chariots drawn by
red, black, white, and
dappled horses
Zec 6:5-8 WEB …
“These are the four
winds of the sky, which
go forth from standing
before the Lord of all
the earth. …” (7) … So
they walked back and
forth through the earth
…
63. In Rev 6:1-8, 4 creatures announce 4
horses with the opening of 4 seals
1st seal – 1st creature
announces 1st rider on a
white horse
2nd seal – 2nd creature
announces 2nd rider on
a red horse
3rd seal – 3rd creature
announces 3rd rider on
a black horse
4th seal – 4th creature
announces 4th rider on
a pale horse
64. The OT mentions the 4 winds & the 4
corners of the earth
4 corners of the earth
from which God gathers
Isa 11:12 WEB He will
… assemble … Israel,
and gather … Judah from
the four corners of the
earth.
4 winds by which God
scatters his enemies
Jer 49:36 WEB On Elam
will I bring the four winds
from the four quarters of
the sky …,
65. Revelation has 4 angels at 4 corners
of the earth holding back judgment
Rev 7:1 WEB I saw
four angels standing at
the four corners of the
earth, holding the four
winds of the earth …
Rev 9:13-15 WEB …
(15) The four angels
were freed who had
been prepared for that
hour and day and
month and year, so that
they might kill one third
of mankind.
66. Ten symbolizes limits
Relates to anatomy: ten fingers on the human hand
Once you’ve counted to ten, you’ve exhausted all of your
fingers, and all of your chances
Many places in the Bible where one counts to ten and
then says: “Enough!”
67. Ten years was limit of Abram's
patience with God's promise
Gen 13:16 WEB I will
make your offspring as
the dust of the earth…
Gen 16:3 WEB
Sarai, Abram's
wife, took Hagar the
Egyptian, her
handmaid, after Abram
had lived ten years in
the land of Canaan, and
gave her to Abram her
husband to be his wife.
68. Ten was the limit of God's patience
with Sodom
Abraham bargained
with God to spare
Sodom, testing God’s
limits till he reached the
ten
Gen 18:32 WEB “Oh
don't let the Lord be
angry … What if ten are
found there?” He said, “I
will not destroy it for the
ten's sake.”
69. Ten changes in terms was the limit of
Jacob's patience with Laban
Gen 31:41 WEB These
twenty years I have
been in your house. I
served you fourteen
years for your two
daughters, and six
years for your flock, and
you have changed my
wages ten times.
70. The Ten Commandments were the
limits God set on Israel's conduct
Exo 34:28 WEB He was
there with Yahweh forty
days and forty nights;
he neither ate bread,
nor drank water. He
wrote on the tablets the
words of the covenant,
the ten commandments.
God gave people ten
chances – as seen in
two other events during
the life of Moses
71. Ten plagues showed the limit of
God's patience with Egypt.
Egypt suffers for Pharaoh's refusal to let Israel go
In spite of plague after plague, Pharaoh continues to
harden his heart
The tenth plague results in final judgment on Egypt
72. Ten rebellions test the limits of God's
patience with the Exodus generation
Num 14:20-23 WEB
Yahweh said, …
because all those men
who have seen my
glory, and my signs …
yet have tempted me
these ten times, and
have not listened to my
voice; surely they shall
not see the land which I
swore to their fathers …
73. The uses of “ten” in Revelation
Pergamum would suffer
ten days before God
said, “Enough!”
Rev 2:10 WEB … the
devil is about to throw
some of you into prison
… and you will have
oppression for ten days.
Be faithful to death, and I
will give you the crown of
life.
Devil is limited by what
God allows him to do!
74. The dragon and the sea beast have
10 horns
Rev 12:3 WEB Behold,
a great red dragon,
having seven heads
and ten horns …
Rev 13:1 WEB I saw a
beast coming up out of
the sea, having ten
horns … On his horns
were ten crowns …
They have power,
(horns), but only the
power God gives them
– God sets their limits!
75. 10 horns are 10 kings – God sets
limits on the beast's power
Rev 17:7 WEB I will tell
you the mystery of the
woman, and of the
beast … which has the
seven heads and the
ten horns.
Rev 17:12 WEB The
ten horns that you saw
are ten kings who have
received no kingdom as
yet, but they receive
authority as kings, with
the beast, for one hour.
76. 1,000 symbolizes limitlessness
Psa 50:10 WEB For
every animal of the
forest is mine, and the
livestock on a thousand
hills.
God is not exempting
the livestock on other
hills, nor the livestock in
valleys. What he’s
saying is that all
livestock belongs to him
77. Apply that reasoning to other
passages:
Deu 7:9 WEB … Yahweh your God … keeps
covenant … with them who love him and keep his
commandments to a thousand generations
Message: God loves everyone who loves and obeys him
Psa 68:17 WEB The chariots of God are tens of
thousands and thousands of thousands …
Message: God has immeasurable power
And when we come to that text about 1,000 years
Time is insignificant to God. Man’s eon is God’s moment
Psa 90:4 WEB For a thousand years in your sight are just like
yesterday when it is past, like a watch in the night.
God’s schedule is not to be judged by man's.
2Pe 3:8 WEB But don't forget … that one day is with the Lord
as a thousand years, and a thousand years as one day.
78. Remember the symbolic use of 1,000
when we get to Rev 20:2-7
He seized the dragon
… and bound him for a
thousand years … I saw
the souls of those who
had been beheaded for
the testimony of Jesus
… They lived, and
reigned with Christ for a
thousand years …
Devil’s power is limited
(10 horns), but God’s
dominion over him is
unlimited (1,000 years)