Please answer the given financial question based on the context.
Context: marathon oil corporation notes to consolidated financial statements ( g ) this obligation relates to a lease of equipment at united states steel 2019s clairton works cokemaking facility in pennsylvania . we are the primary obligor under this lease . under the financial matters agreement , united states steel has assumed responsibility for all obligations under this lease . this lease is an amortizing financing with a final maturity of 2012 . ( h ) these notes are senior secured notes of marathon oil canada corporation . the notes are secured by substantially all of marathon oil canada corporation 2019s assets . in january 2008 , we provided a full and unconditional guarantee covering the payment of all principal and interest due under the senior notes . ( i ) these obligations as of december 31 , 2009 include $ 36 million related to assets under construction at that date for which a capital lease will commence upon completion of construction . the amounts currently reported are based upon the percent of construction completed as of december 31 , 2009 and therefore do not reflect future minimum lease obligations of $ 164 million related to the asset . ( j ) payments of long-term debt for the years 2010 - 2014 are $ 102 million , $ 246 million , $ 1492 million , $ 287 million and $ 802 million . united steel is due to pay $ 17 million in 2010 , $ 161 million in 2011 , $ 19 million in 2012 , and $ 11 for year 2014 . ( k ) in the event of a change in control , as defined in the related agreements , debt obligations totaling $ 662 million at december 31 , 2009 , may be declared immediately due and payable . ( l ) see note 16 for information on interest rate swaps . 20 . asset retirement obligations the following summarizes the changes in asset retirement obligations : ( in millions ) 2009 2008 .
|( in millions )|2009|2008|
|asset retirement obligations as of january 1|$ 965|$ 1134|
|liabilities incurred including acquisitions|14|30|
|liabilities settled|-65 ( 65 )|-94 ( 94 )|
|accretion expense ( included in depreciation depletion and amortization )|64|66|
|revisions to previous estimates|124|24|
|held for sale|-|-195 ( 195 )|
|asset retirement obligations as of december 31 ( a )|$ 1102|$ 965|
asset retirement obligations as of december 31 ( a ) $ 1102 $ 965 ( a ) includes asset retirement obligation of $ 3 and $ 2 million classified as short-term at december 31 , 2009 , and 2008. .
Question: by what percentage did asset retirement obligations decrease from 2007 to 2008?


Answer: The answer is:-0.14903