providing a revolving credit facility of $ 7.0 billion and expiring on october 17 , 2008 .interest on any amounts we borrow under these facilities would be charged at 90-day libor plus 15 basis points .at december 31 , 2007 , there were no outstanding borrowings under these facilities .our existing debt instruments and credit facilities do not have cross-default or ratings triggers , however these debt instruments and credit facilities do subject us to certain financial covenants .covenants in our credit facilities generally require us to maintain a $ 3.0 billion minimum net worth and limit the amount of secured indebtedness that may be incurred by the company .the notes issued in january 2008 include limitations on secured indebtedness and on sale-leaseback transactions .these covenants are not considered material to the overall financial condition of the company , and all applicable covenant tests were satisfied as of december 31 , commitments we have contractual obligations and commitments in the form of capital leases , operating leases , debt obligations , purchase commitments , and certain other liabilities .we intend to satisfy these obligations through the use of cash flow from operations .the following table summarizes the expected cash outflow to satisfy our contractual obligations and commitments as of december 31 , 2007 ( in millions ) : capital leases operating leases principal interest purchase commitments pension fundings liabilities .
[['year', 'capital leases', 'operating leases', 'debt principal', 'debt interest', 'purchase commitments', 'pension fundings', 'other liabilities'], ['2008', '$ 108', '$ 378', '$ 3426', '$ 329', '$ 1306', '$ 101', '$ 78'], ['2009', '73', '325', '83', '384', '791', '824', '74'], ['2010', '91', '237', '40', '380', '729', '630', '71'], ['2011', '31', '166', '33', '379', '698', '717', '69'], ['2012', '31', '116', '26', '377', '304', '859', '67'], ['after 2012', '285', '560', '6919', '6177', '2014', '334', '203'], ['total', '$ 619', '$ 1782', '$ 10527', '$ 8026', '$ 3828', '$ 3465', '$ 562']]
our capital lease obligations relate primarily to leases on aircraft .capital leases , operating leases , and purchase commitments , as well as our debt principal obligations , are discussed further in note 8 to our consolidated financial statements .the amount of interest on our debt was calculated as the contractual interest payments due on our fixed-rate debt , in addition to interest on variable rate debt that was calculated based on interest rates as of december 31 , 2007 .the calculations of debt interest do not take into account the effect of interest rate swap agreements .the maturities of debt principal and interest include the effect of the january 2008 issuance of $ 4.0 billion in senior notes that were used to reduce the commercial paper balance .purchase commitments represent contractual agreements to purchase goods or services that are legally binding , the largest of which are orders for aircraft , engines , and parts .in february 2007 , we announced an order for 27 boeing 767-300er freighters to be delivered between 2009 and 2012 .we also have firm commitments to purchase nine boeing 747-400f aircraft scheduled for delivery between 2008 and 2010 , and two boeing 747-400bcf aircraft scheduled for delivery during 2008 .these aircraft purchase orders will provide for the replacement of existing capacity and anticipated future growth .in july 2007 , we formally cancelled our previous order for ten airbus a380-800 freighter aircraft , pursuant to the provisions of an agreement signed with airbus in february 2007 .as a result of our cancellation of the airbus a380-800 order , we received cash in july 2007 representing the return of amounts previously paid to airbus as purchase contract deposits and accrued interest on those balances .additionally , we received a credit memorandum to be used by ups for the purchase of parts and services from airbus .the cancellation of the airbus order did not have a material impact on our financial condition , results of operations , or liquidity. .

Question: what portion of total expected cash outflow for capital leases is due in 2018?
Answer: 17.4%