item 7 .
management 2019s discussion and analysis of financial condition and results of operations we are a global integrated energy company with significant operations in the north america , africa and europe .
our operations are organized into four reportable segments : 2022 exploration and production ( 201ce&p 201d ) which explores for , produces and markets liquid hydrocarbons and natural gas on a worldwide basis .
2022 oil sands mining ( 201cosm 201d ) 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 2022 integrated gas ( 201cig 201d ) which markets and transports products manufactured from natural gas , such as liquefied natural gas ( 201clng 201d ) and methanol , on a worldwide basis .
2022 refining , marketing & transportation ( 201crm&t 201d ) which refines , markets and transports crude oil and petroleum products , primarily in the midwest , upper great plains , gulf coast and southeastern regions of the united states .
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 the forward-looking statements .
we hold a 60 percent interest in equatorial guinea lng holdings limited ( 201cegholdings 201d ) .
as discussed in note 4 to the consolidated financial statements , effective may 1 , 2007 , we ceased consolidating egholdings .
our investment is accounted for using the equity method of accounting .
unless specifically noted , amounts presented for the integrated gas segment for periods prior to may 1 , 2007 , include amounts related to the minority interests .
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 , item 6 .
selected financial data and item 8 .
financial statements and supplementary data .
overview 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 were volatile in 2009 , but not as much as in the previous year .
prices in 2009 were also lower than in recent years as illustrated by the annual averages for key benchmark prices below. .

Benchmark
2009
2008
2007
WTI crude oil (Dollars per barrel)
$62.09
$99.75
$72.41
Dated Brent crude oil (Dollars per barrel)
$61.67
$97.26
$72.39
Henry Hub natural gas (Dollars per mcf)<sup>(a)</sup>
$3.99
$9.04
$6.86

henry hub natural gas ( dollars per mcf ) ( a ) $ 3.99 $ 9.04 $ 6.86 ( a ) first-of-month price index .
crude oil prices rose sharply through the first half of 2008 as a result of strong global demand , a declining dollar , ongoing concerns about supplies of crude oil , and geopolitical risk .
later in 2008 , crude oil prices sharply declined as the u.s .
dollar rebounded and global demand decreased as a result of economic recession .
the price decrease continued into 2009 , but reversed after dropping below $ 33.98 in february , ending the year at $ 79.36 .
our domestic crude oil production is about 62 percent sour , which means that it 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 dated brent crude benchmark .
the differential between wti and dated brent average prices narrowed to $ 0.42 in 2009 compared to $ 2.49 in 2008 and $ 0.02 in 2007. .

Question: Analyse this data from a financial earnings document. by what percentage did the average henry hub natural gas benchmark decrease from 2007 to 2009?
Choices:
-0.31748
-0.41837
-2.39024
-47.80488
-2.87
Correct choice index: 1