bhge 2018 form 10-k | 41 estimate would equal up to 5% ( 5 % ) of annual revenue .
the expenditures are expected to be used primarily for normal , recurring items necessary to support our business .
we also anticipate making income tax payments in the range of $ 425 million to $ 475 million in 2019 .
contractual obligations in the table below , we set forth our contractual obligations as of december 31 , 2018 .
certain amounts included in this table are based on our estimates and assumptions about these obligations , including their duration , anticipated actions by third parties and other factors .
the contractual obligations we will actually pay in future periods may vary from those reflected in the table because the estimates and assumptions are subjective. .

( in millions )
payments due by period total
payments due by period less than1 year
payments due by period 1 - 3years
payments due by period 4 - 5years
payments due by period more than5 years
total debt and capital lease obligations ( 1 )
$ 6989
$ 942
$ 562
$ 1272
$ 4213
estimated interest payments ( 2 )
3716
239
473
404
2600
operating leases ( 3 )
846
186
262
132
266
purchase obligations ( 4 )
1507
1388
86
25
8
total
$ 13058
$ 2755
$ 1383
$ 1833
$ 7087

( 1 ) amounts represent the expected cash payments for the principal amounts related to our debt , including capital lease obligations .
amounts for debt do not include any deferred issuance costs or unamortized discounts or premiums including step up in the value of the debt on the acquisition of baker hughes .
expected cash payments for interest are excluded from these amounts .
total debt and capital lease obligations includes $ 896 million payable to ge and its affiliates .
as there is no fixed payment schedule on the amount payable to ge and its affiliates we have classified it as payable in less than one year .
( 2 ) amounts represent the expected cash payments for interest on our long-term debt and capital lease obligations .
( 3 ) amounts represent the future minimum payments under noncancelable operating leases with initial or remaining terms of one year or more .
we enter into operating leases , some of which include renewal options , however , we have excluded renewal options from the table above unless it is anticipated that we will exercise such renewals .
( 4 ) purchase obligations include expenditures for capital assets for 2019 as well as agreements to purchase goods or services that are enforceable and legally binding and that specify all significant terms , including : fixed or minimum quantities to be purchased ; fixed , minimum or variable price provisions ; and the approximate timing of the transaction .
due to the uncertainty with respect to the timing of potential future cash outflows associated with our uncertain tax positions , we are unable to make reasonable estimates of the period of cash settlement , if any , to the respective taxing authorities .
therefore , $ 597 million in uncertain tax positions , including interest and penalties , have been excluded from the contractual obligations table above .
see "note 12 .
income taxes" of the notes to consolidated and combined financial statements in item 8 herein for further information .
we have certain defined benefit pension and other post-retirement benefit plans covering certain of our u.s .
and international employees .
during 2018 , we made contributions and paid direct benefits of approximately $ 72 million in connection with those plans , and we anticipate funding approximately $ 41 million during 2019 .
amounts for pension funding obligations are based on assumptions that are subject to change , therefore , we are currently not able to reasonably estimate our contribution figures after 2019 .
see "note 11 .
employee benefit plans" of the notes to consolidated and combined financial statements in item 8 herein for further information .
off-balance sheet arrangements in the normal course of business with customers , vendors and others , we have entered into off-balance sheet arrangements , such as surety bonds for performance , letters of credit and other bank issued guarantees , which totaled approximately $ 3.6 billion at december 31 , 2018 .
it is not practicable to estimate the fair value of these financial instruments .
none of the off-balance sheet arrangements either has , or is likely to have , a material effect on our consolidated and combined financial statements. .

Question: what are the combined total operating leases and purchase obligations as a percentage of the total payments due?
Answer: 18.0%