{"pre_text": ["a significant portion of our natural gas production in the lower 48 states of the u.s .", "is sold at bid-week prices or first-of-month indices relative to our specific producing areas .", "average settlement date henry hub natural gas prices have been relatively stable for the periods of this report ; however , a decline began in september 2011 which has continued in 2012 with february averaging $ 2.68 per mmbtu .", "should u.s .", "natural gas prices remain depressed , an impairment charge related to our natural gas assets may be necessary .", "our other major natural gas-producing regions are europe and eg .", "natural gas prices in europe have been significantly higher than in the u.s .", "in the case of eg our natural gas sales are subject to term contracts , making realized prices less volatile .", "the natural gas sales from eg are at fixed prices ; therefore , our worldwide reported average natural gas realized prices may not fully track market price movements .", "oil sands mining osm segment revenues correlate with prevailing market prices for the various qualities of synthetic crude oil we produce .", "roughly two-thirds of the normal output mix will track movements in wti and one-third will track movements in the canadian heavy sour crude oil marker , primarily western canadian select .", "output mix can be impacted by operational problems or planned unit outages at the mines or the upgrader .", "the operating cost structure of the oil sands mining operations is predominantly fixed and therefore many of the costs incurred in times of full operation continue during production downtime .", "per-unit costs are sensitive to production rates .", "key variable costs are natural gas and diesel fuel , which track commodity markets such as the canadian alberta energy company ( 201caeco 201d ) natural gas sales index and crude oil prices , respectively .", "recently aeco prices have declined , much as henry hub prices have .", "we would expect a significant , continued declined in natural gas prices to have a favorable impact on osm operating costs .", "the table below shows average benchmark prices that impact both our revenues and variable costs. ."], "post_text": ["wti crude oil ( dollars per bbl ) $ 95.11 $ 79.61 $ 62.09 western canadian select ( dollars per bbl ) ( a ) 77.97 65.31 52.13 aeco natural gas sales index ( dollars per mmbtu ) ( b ) $ 3.68 $ 3.89 $ 3.49 ( a ) monthly pricing based upon average wti adjusted for differentials unique to western canada .", "( b ) monthly average day ahead index .", "integrated gas our integrated gas operations include production and marketing of products manufactured from natural gas , such as lng and methanol , in eg .", "world lng trade in 2011 has been estimated to be 241 mmt .", "long-term , lng continues to be in demand as markets seek the benefits of clean burning natural gas .", "market prices for lng are not reported or posted .", "in general , lng delivered to the u.s .", "is tied to henry hub prices and will track with changes in u.s .", "natural gas prices , while lng sold in europe and asia is indexed to crude oil prices and will track the movement of those prices .", "we have a 60 percent ownership in an lng production facility in equatorial guinea , which sells lng under a long-term contract at prices tied to henry hub natural gas prices .", "gross sales from the plant were 4.1 mmt , 3.7 mmt and 3.9 mmt in 2011 , 2010 and 2009 .", "we own a 45 percent interest in a methanol plant located in equatorial guinea through our investment in ampco .", "gross sales of methanol from the plant totaled 1039657 , 850605 and 960374 metric tonnes in 2011 , 2010 and 2009 .", "methanol demand has a direct impact on ampco 2019s earnings .", "because global demand for methanol is rather limited , changes in the supply-demand balance can have a significant impact on sales prices .", "world demand for methanol in 2011 has been estimated to be 55.4 mmt .", "our plant capacity of 1.1 mmt is about 2 percent of total demand .", "operating and financial highlights significant operating and financial highlights during 2011 include : 2022 completed the spin-off of our downstream business on june 30 , 2011 2022 acquired a significant operated position in the eagle ford shale play in south texas 2022 added net proved reserves , for the e&p and osm segments combined , of 307 mmboe , excluding dispositions , for a 212 percent reserve replacement ratio ."], "table": [["benchmark", "2011", "2010", "2009"], ["wti crude oil ( dollars per bbl )", "$ 95.11", "$ 79.61", "$ 62.09"], ["western canadian select ( dollars per bbl ) ( a )", "77.97", "65.31", "52.13"], ["aeco natural gas sales index ( dollars per mmbtu ) ( b )", "$ 3.68", "$ 3.89", "$ 3.49"]], "table_ori": [["Benchmark", "2011", "2010", "2009"], ["WTI crude oil<i>(Dollars per bbl)</i>", "$95.11", "$79.61", "$62.09"], ["Western Canadian Select<i>(Dollars per bbl)</i><sup>(a)</sup>", "77.97", "65.31", "52.13"], ["AECO natural gas sales index<i>(Dollars per mmbtu)</i><sup>(b)</sup>", "$3.68", "$3.89", "$3.49"]]}

Question: how much has the western canadian select dollars per bbl increased since 2009?
Evidence:
table_2: benchmark the western canadian select ( dollars per bbl ) ( a ) of 2011 is 77.97 ; the western canadian select ( dollars per bbl ) ( a ) of 2010 is 65.31 ; the western canadian select ( dollars per bbl ) ( a ) of 2009 is 52.13 ;
Program: subtract(77.97, 52.13), divide(#0, 52.13)
Answer:
str_answer: 49.6%
exe_answer: 0.49568