{"pre_text": ["item 7 .", "management 2019s discussion and analysis of financial condition and results of operations we are an international energy company with operations in the u.s. , canada , africa , the middle east and europe .", "our operations are organized into three reportable segments : 2022 e&p which explores for , produces and markets liquid hydrocarbons and natural gas on a worldwide basis .", "2022 osm which mines , extracts and transports bitumen from oil sands deposits in alberta , canada , and upgrades the bitumen to produce and market synthetic crude oil and vacuum gas oil .", "2022 ig which produces and markets products manufactured from natural gas , such as lng and methanol , in eg .", "certain sections of management 2019s discussion and analysis of financial condition and results of operations include forward-looking statements concerning trends or events potentially affecting our business .", "these statements typically contain words such as 201canticipates , 201d 201cbelieves , 201d 201cestimates , 201d 201cexpects , 201d 201ctargets , 201d 201cplans , 201d 201cprojects , 201d 201ccould , 201d 201cmay , 201d 201cshould , 201d 201cwould 201d or similar words indicating that future outcomes are uncertain .", "in accordance with 201csafe harbor 201d provisions of the private securities litigation reform act of 1995 , these statements are accompanied by cautionary language identifying important factors , though not necessarily all such factors , which could cause future outcomes to differ materially from those set forth in forward-looking statements .", "for additional risk factors affecting our business , see item 1a .", "risk factors in this annual report on form 10-k .", "management 2019s discussion and analysis of financial condition and results of operations should be read in conjunction with the information under item 1 .", "business , item 1a .", "risk factors and item 8 .", "financial statements and supplementary data found in this annual report on form 10-k .", "spin-off downstream business on june 30 , 2011 , the spin-off of marathon 2019s downstream business was completed , creating two independent energy companies : marathon oil and mpc .", "marathon shareholders at the close of business on the record date of june 27 , 2011 received one share of mpc common stock for every two shares of marathon common stock held .", "fractional shares of mpc common stock were not distributed and any fractional share of mpc common stock otherwise issuable to a marathon shareholder was sold in the open market on such shareholder 2019s behalf , and such shareholder received a cash payment with respect to that fractional share .", "a private letter tax ruling received in june 2011 from the irs affirmed the tax-free nature of the spin-off .", "activities related to the downstream business have been treated as discontinued operations in all periods presented in this annual report on form 10-k ( see item 8 .", "financial statements and supplementary data 2014note 3 to the consolidated financial statements for additional information ) .", "overview 2013 market conditions exploration and production prevailing prices for the various grades of crude oil and natural gas that we produce significantly impact our revenues and cash flows .", "prices of crude oil have been volatile in recent years .", "in 2011 , crude prices increased over 2010 levels , with increases in brent averages outstripping those in wti .", "during much of 2010 , both wti and brent crude oil monthly average prices remained in the $ 75 to $ 85 per barrel range .", "crude oil prices reached a low of $ 33.98 in february 2009 , following global demand declines in an economic recession , but recovered quickly ending 2009 at $ 79.36 .", "the following table lists benchmark crude oil and natural gas price annual averages for the past three years. ."], "post_text": ["wti crude oil ( dollars per bbl ) $ 95.11 $ 79.61 $ 62.09 brent ( europe ) crude oil ( dollars per bbl ) 111.26 79.51 61.49 henry hub natural gas ( dollars per mmbtu ) ( a ) $ 4.04 $ 4.39 $ 3.99 ( a ) settlement date average .", "our u.s .", "crude oil production was approximately 58 percent sour in 2011 and 68 percent in 2010 .", "sour crude contains more sulfur than light sweet wti does .", "sour crude oil also tends to be heavier than light sweet crude oil and sells at a discount to light sweet crude oil because of higher refining costs and lower refined product values .", "our international crude oil production is relatively sweet and is generally sold in relation to the brent crude benchmark .", "the differential between wti and brent average prices widened significantly in 2011 to $ 16.15 in comparison to differentials of less than $ 1.00 in 2010 and 2009. ."], "table": [["benchmark", "2011", "2010", "2009"], ["wti crude oil ( dollars per bbl )", "$ 95.11", "$ 79.61", "$ 62.09"], ["brent ( europe ) crude oil ( dollars per bbl )", "111.26", "79.51", "61.49"], ["henry hub natural gas ( dollars per mmbtu ) ( a )", "$ 4.04", "$ 4.39", "$ 3.99"]], "table_ori": [["Benchmark", "2011", "2010", "2009"], ["WTI crude oil<i>(Dollars per bbl)</i>", "$95.11", "$79.61", "$62.09"], ["Brent (Europe) crude oil<i>(Dollars per bbl)</i>", "111.26", "79.51", "61.49"], ["Henry Hub natural gas<i>(Dollars per mmbtu)</i><sup>(a)</sup>", "$4.04", "$4.39", "$3.99"]]}

Question: what was the approximate differential between wti and brent average prices in 2011 in comparison to differentials in 2010 and 2009?
Evidence:
text_32: the differential between wti and brent average prices widened significantly in 2011 to $ 16.15 in comparison to differentials of less than $ 1.00 in 2010 and 2009. .
Program: subtract(16.15, 1.00)
Answer:
str_answer: 15.15
exe_answer: 15.15