contractual 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 , 2010 ( in millions ) : .

commitment type
2011
2012
2013
2014
2015
after 2016
total
capital leases
$ 18
$ 19
$ 19
$ 20
$ 21
$ 112
$ 209
operating leases
348
268
205
150
113
431
1515
debt principal
345
2014
1750
1000
100
7363
10558
debt interest
322
321
300
274
269
4940
6426
purchase commitments
642
463
425
16
2014
2014
1546
pension fundings
1200
196
752
541
274
2014
2963
other liabilities
69
67
64
58
43
38
339
total
$ 2944
$ 1334
$ 3515
$ 2059
$ 820
$ 12884
$ 23556

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 7 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 , 2010 .
the calculations of debt interest take into account the effect of interest rate swap agreements .
for debt denominated in a foreign currency , the u.s .
dollar equivalent principal amount of the debt at the end of the year was used as the basis to calculate future interest payments .
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 .
as of december 31 , 2010 , we have firm commitments to purchase 20 boeing 767-300er freighters to be delivered between 2011 and 2013 , and two boeing 747-400f aircraft scheduled for delivery during 2011 .
these aircraft purchase orders will provide for the replacement of existing capacity and anticipated future growth .
pension fundings represent the anticipated required cash contributions that will be made to our qualified pension plans .
these contributions include those to the ups ibt pension plan , which was established upon ratification of the national master agreement with the teamsters , as well as the ups pension plan .
these plans are discussed further in note 5 to the consolidated financial statements .
the pension funding requirements were estimated under the provisions of the pension protection act of 2006 and the employee retirement income security act of 1974 , using discount rates , asset returns , and other assumptions appropriate for these plans .
to the extent that the funded status of these plans in future years differs from our current projections , the actual contributions made in future years could materially differ from the amounts shown in the table above .
additionally , we have not included minimum funding requirements beyond 2015 , because these projected contributions are not reasonably determinable .
we are not subject to any minimum funding requirement for cash contributions in 2011 in the ups retirement plan or ups pension plan .
the amount of any minimum funding requirement , as applicable , for these plans could change significantly in future periods , depending on many factors , including future plan asset returns and discount rates .
a sustained significant decline in the world equity markets , and the resulting impact on our pension assets and investment returns , could result in our domestic pension plans being subject to significantly higher minimum funding requirements .
such an outcome could have a material adverse impact on our financial position and cash flows in future periods .
the contractual payments due for 201cother liabilities 201d primarily include commitment payments related to our investment in certain partnerships .
the table above does not include approximately $ 284 million of liabilities for .

Question: what percentage of contractual obligations and commitments in total are debt principal and debt interest?
Answer: 72%
Calculation: add(10558, 6426), divide(#0, 23556)