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 2014 ( in mmboe ) . .

u.s .: proved undeveloped reserves as of december 31 2013: 258
extensions and discoveries: 153
revisions due to prices: -1
revisions other than price: -61
sale of reserves: -4
conversion to proved developed reserves: -40
proved undeveloped reserves as of december 31 2014: 305
canada: proved undeveloped reserves as of december 31 2013: 443
extensions and discoveries: 8
revisions due to prices: -34
revisions other than price: 18
sale of reserves: -2
conversion to proved developed reserves: -49
proved undeveloped reserves as of december 31 2014: 384
total: proved undeveloped reserves as of december 31 2013: 701
extensions and discoveries: 161
revisions due to prices: -35
revisions other than price: -43
sale of reserves: -6
conversion to proved developed reserves: -89
proved undeveloped reserves as of december 31 2014: 689

at december 31 , 2014 , devon had 689 mmboe of proved undeveloped reserves . this represents a 2 percent decrease as compared to 2013 and represents 25 percent of total proved reserves . drilling and development activities increased devon 2019s proved undeveloped reserves 161 mmboe and resulted in the conversion of 89 mmboe , or 13 percent , of the 2013 proved undeveloped reserves to proved developed reserves . costs incurred related to the development and conversion of devon 2019s proved undeveloped reserves were approximately $ 1.0 billion for 2014 . additionally , revisions other than price decreased devon 2019s proved undeveloped reserves 43 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 , which were approximately 69 mmboe , relate to the dry-gas areas in the barnett shale in north texas . a significant amount of devon 2019s proved undeveloped reserves at the end of 2014 related to its jackfish operations . at december 31 , 2014 and 2013 , devon 2019s jackfish proved undeveloped reserves were 384 mmboe and 441 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 and steam-oil ratios . furthermore , development of these projects involves the up-front construction of steam injection/distribution and bitumen processing facilities . due to the large up-front capital investments and large reserves required to provide economic returns , the project conditions meet the specific circumstances requiring a period greater than 5 years for conversion to developed reserves . 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 2014 2013 reserves increased 9 mmboe primarily due to higher gas prices in the barnett shale and the anadarko basin , partially offset by higher bitumen prices , which result in lower after-royalty volumes , in canada . 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. .

Questions:
what was the change in the proved undeveloped reserves from 2013 to 2014?
and how much does this change represent in relation to the proved undeveloped reserves in 2013, in percentage?

Answers:
-12
-1.7%