devon energy corporation and subsidiaries notes to consolidated financial statements 2013 ( continued ) proved undeveloped reserves the following table presents the changes in devon 2019s total proved undeveloped reserves during 2013 ( in mmboe ) . .

U.S.
Canada
Total
Proved undeveloped reserves as of December 31, 2012
407
433
840
Extensions and discoveries
57
38
95
Revisions due to prices
1
(10)
(9)
Revisions other than price
(91)
13
(78)
Conversion to proved developed reserves
(116)
(31)
(147)
Proved undeveloped reserves as of December 31, 2013
258
443
701

at december 31 , 2013 , devon had 701 mmboe of proved undeveloped reserves .
this represents a 17 percent decrease as compared to 2012 and represents 24 percent of total proved reserves .
drilling and development activities increased devon 2019s proved undeveloped reserves 95 mmboe and resulted in the conversion of 147 mmboe , or 18 percent , of the 2012 proved undeveloped reserves to proved developed reserves .
costs incurred related to the development and conversion of devon 2019s proved undeveloped reserves were $ 1.9 billion for 2013 .
additionally , revisions other than price decreased devon 2019s proved undeveloped reserves 78 mmboe primarily due to evaluations of certain u.s .
onshore dry-gas areas , which devon does not expect to develop in the next five years .
the largest revisions relate to the dry-gas areas in the cana-woodford shale in western oklahoma , carthage in east texas and the barnett shale in north texas .
a significant amount of devon 2019s proved undeveloped reserves at the end of 2013 related to its jackfish operations .
at december 31 , 2013 and 2012 , devon 2019s jackfish proved undeveloped reserves were 441 mmboe and 429 mmboe , respectively .
development schedules for the jackfish reserves are primarily controlled by the need to keep the processing plants at their 35000 barrel daily facility capacity .
processing plant capacity is controlled by factors such as total steam processing capacity , steam-oil ratios and air quality discharge permits .
as a result , these reserves are classified as proved undeveloped for more than five years .
currently , the development schedule for these reserves extends though the year 2031 .
price revisions 2013 2013 reserves increased 94 mmboe primarily due to higher gas prices .
of this increase , 43 mmboe related to the barnett shale and 19 mmboe related to the rocky mountain area .
2012 2013 reserves decreased 171 mmboe primarily due to lower gas prices .
of this decrease , 100 mmboe related to the barnett shale and 25 mmboe related to the rocky mountain area .
2011 2013 reserves decreased 21 mmboe due to lower gas prices and higher oil prices .
the higher oil prices increased devon 2019s canadian royalty burden , which reduced devon 2019s oil reserves .
revisions other than price total revisions other than price for 2013 , 2012 and 2011 primarily related to devon 2019s evaluation of certain dry gas regions , with the largest revisions being made in the cana-woodford shale , barnett shale and carthage .

Question: Analyse this data from a financial earnings document. what percentage decrease was there from the 2012 proved undeveloped reserves to 2013 proved undeveloped reserves?
Choices:
42.01474
10000
36.60934
99.53317
57.75194
Correct choice index: 2