Financial report context:
marathon oil corporation notes to consolidated financial statements the changes in the carrying amount of goodwill for the years ended december 31 , 2007 , and 2008 , were as follows : ( in millions ) e&p osm rm&t total .

Financial table:
( in millions ): balance as of december 31 2006; e&p: $ 519; osm: $ 2013; rm&t: $ 879; total: $ 1398
( in millions ): acquired; e&p: 71; osm: 1437; rm&t: 2013; total: 1508
( in millions ): adjusted ( a ); e&p: 2013; osm: 2013; rm&t: -7 ( 7 ); total: -7 ( 7 )
( in millions ): balance as of december 31 2007; e&p: 590; osm: 1437; rm&t: 872; total: 2899
( in millions ): adjusted ( a ); e&p: -17 ( 17 ); osm: -25 ( 25 ); rm&t: 7; total: -35 ( 35 )
( in millions ): impaired; e&p: 2013; osm: -1412 ( 1412 ); rm&t: 2013; total: -1412 ( 1412 )
( in millions ): disposed ( b ); e&p: -5 ( 5 ); osm: 2013; rm&t: -5 ( 5 )
( in millions ): balance as of december 31 2008; e&p: $ 568; osm: $ 2013; rm&t: $ 879; total: $ 1447

Additional report context:
( a ) adjustments related to prior period income tax and royalty adjustments . ( b ) goodwill was allocated to the norwegian outside-operated properties sold in 2008 . 17 . fair value measurements as defined in sfas no . 157 , fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date . sfas no . 157 describes three approaches to measuring the fair value of assets and liabilities : the market approach , the income approach and the cost approach , each of which includes multiple valuation techniques . the market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities . the income approach uses valuation techniques to measure fair value by converting future amounts , such as cash flows or earnings , into a single present value amount using current market expectations about those future amounts . the cost approach is based on the amount that would currently be required to replace the service capacity of an asset . this is often referred to as current replacement cost . the cost approach assumes that the fair value would not exceed what it would cost a market participant to acquire or construct a substitute asset of comparable utility , adjusted for obsolescence . sfas no . 157 does not prescribe which valuation technique should be used when measuring fair value and does not prioritize among the techniques . sfas no . 157 establishes a fair value hierarchy that prioritizes the inputs used in applying the various valuation techniques . inputs broadly refer to the assumptions that market participants use to make pricing decisions , including assumptions about risk . level 1 inputs are given the highest priority in the fair value hierarchy while level 3 inputs are given the lowest priority . the three levels of the fair value hierarchy are as follows . 2022 level 1 2013 observable inputs that reflect unadjusted quoted prices for identical assets or liabilities in active markets as of the reporting date . active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis . 2022 level 2 2013 observable market-based inputs or unobservable inputs that are corroborated by market data . these are inputs other than quoted prices in active markets included in level 1 , which are either directly or indirectly observable as of the reporting date . 2022 level 3 2013 unobservable inputs that are not corroborated by market data and may be used with internally developed methodologies that result in management 2019s best estimate of fair value . we use a market or income approach for recurring fair value measurements and endeavor to use the best information available . accordingly , valuation techniques that maximize the use of observable inputs are favored . financial assets and liabilities are classified in their entirety based on the lowest priority level of input that is significant to the fair value measurement . the assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the placement of assets and liabilities within the levels of the fair value hierarchy. .

Question: by what percentage did total goodwill decline from 2007 to 2008 year end?
Answer: -50.1%