by what percentage did asset retirement obligations increase from 2008 to 2009?
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 .

| <i>(In millions)</i> | 2009 | 2008 |
| :--- | :--- | :--- |
| Asset retirement obligations as of January 1 | $965 | $1,134 |
| Liabilities incurred, including acquisitions | 14 | 30 |
| Liabilities settled | (65) | (94) |
| Accretion expense (included in depreciation, depletion and amortization) | 64 | 66 |
| Revisions to previous estimates | 124 | 24 |
| Held for sale | - | (195) |
| Asset retirement obligations as of December 31<sup>(a)</sup> | $1,102 | $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. .

retirement_obligations_2009 = 1102
retirement_obligations_2008 = 965
increase = retirement_obligations_2009 - retirement_obligations_2008
percent_increase = increase / retirement_obligations_2008
answer = percent_increase * 100