{"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 )"], ["2007", "309"], ["2008", "25"], ["2009", "50"], ["2010", "39"], ["2011", "1485"], ["thereafter ( 1 )", "1590"], ["total", "3498"]], "table_ori": [["", "Total  (In $ millions)"], ["2007", "309"], ["2008", "25"], ["2009", "50"], ["2010", "39"], ["2011", "1,485"], ["Thereafter(1)", "1,590"], ["Total", "3,498"]]}

Question: what is the average of the principal payments scheduled from 2007 to 2011
Evidence:
table_7: the total of total ( in $ millions ) is 3498 ;
table_6: the thereafter ( 1 ) of total ( in $ millions ) is 1590 ;
Program: subtract(3498, 1590), add(#0, const_5), divide(#1, const_2)
Answer:
str_answer: 381.6
exe_answer: 956.5