pre_text: 2022 designate subsidiaries as unrestricted subsidiaries ; and 2022 sell certain assets or merge with or into other companies . subject to certain exceptions , the indentures governing the senior subordinated notes and the senior discount notes permit the issuers of the notes and their restricted subsidiaries to incur additional indebtedness , including secured indebtedness . in addition , the senior credit facilities require bcp crystal to maintain the following financial covenants : a maximum total leverage ratio , a maximum bank debt leverage ratio , a minimum interest coverage ratio and maximum capital expenditures limitation . the maximum consolidated net bank debt to adjusted ebitda ratio , as defined , previously required under the senior credit facilities , was eliminated when the company amended the facilities in january 2005 . as of december 31 , 2006 , the company was in compliance with all of the financial covenants related to its debt agreements . principal payments scheduled to be made on the company 2019s debt , including short term borrowings , is as follows : ( in $ millions ) .
post_text: ( 1 ) includes $ 2 million purchase accounting adjustment to assumed debt . 17 . benefit obligations pension obligations . pension obligations are established for benefits payable in the form of retirement , disability and surviving dependent pensions . the benefits offered vary according to the legal , fiscal and economic conditions of each country . the commitments result from participation in defined contribution and defined benefit plans , primarily in the u.s . benefits are dependent on years of service and the employee 2019s compensation . supplemental retirement benefits provided to certain employees are non-qualified for u.s . tax purposes . separate trusts have been established for some non-qualified plans . the company sponsors defined benefit pension plans in north america , europe and asia . as of december 31 , 2006 , the company 2019s u.s . qualified pension plan represented greater than 84% ( 84 % ) and 76% ( 76 % ) of celanese 2019s pension plan assets and liabilities , respectively . independent trusts or insurance companies administer the majority of these plans . pension costs under the company 2019s retirement plans are actuarially determined . the company sponsors various defined contribution plans in north america , europe , and asia covering certain employees . employees may contribute to these plans and the company will match these contributions in varying amounts . the company 2019s matching contribution to the defined contribution plans are based on specified percentages of employee contributions and aggregated $ 11 million , $ 12 million , $ 8 million and $ 3 million for the years ended december 31 , 2006 and 2005 , the nine months ended december 31 , 2004 and the three months ended march 31 , 2004 , respectively . celanese corporation and subsidiaries notes to consolidated financial statements 2014 ( continued ) .
table: Total  (In $ millions)
table: 2007 309
table: 2008 25
table: 2009 50
table: 2010 39
table: 2011 1,485
table: Thereafter(1) 1,590
table: Total 3,498
question: Analyse this data from a financial earnings document. what is the average of the principal payments scheduled from 2007 to 2011