repurchase programs . we utilized cash generated from operating activities , $ 57.0 million in cash proceeds received from employee stock compensation plans and borrowings under credit facilities to fund the repurchases . during 2008 , we borrowed $ 330.0 million from our existing credit facilities to fund stock repurchases and partially fund the acquisition of abbott spine . we may use excess cash or further borrow from our credit facilities to repurchase additional common stock under the $ 1.25 billion program which expires december 31 , 2009 . we have a five year $ 1350 million revolving , multi- currency , senior unsecured credit facility maturing november 30 , 2012 ( the 201csenior credit facility 201d ) . we had $ 460.1 million outstanding under the senior credit facility at december 31 , 2008 , and an availability of $ 889.9 million . the senior credit facility contains provisions by which we can increase the line to $ 1750 million and request that the maturity date be extended for two additional one-year periods . we and certain of our wholly owned foreign subsidiaries are the borrowers under the senior credit facility . borrowings under the senior credit facility are used for general corporate purposes and bear interest at a libor- based rate plus an applicable margin determined by reference to our senior unsecured long-term credit rating and the amounts drawn under the senior credit facility , at an alternate base rate , or at a fixed rate determined through a competitive bid process . the senior credit facility contains customary affirmative and negative covenants and events of default for an unsecured financing arrangement , including , among other things , limitations on consolidations , mergers and sales of assets . financial covenants include a maximum leverage ratio of 3.0 to 1.0 and a minimum interest coverage ratio of 3.5 to 1.0 . if we fall below an investment grade credit rating , additional restrictions would result , including restrictions on investments , payment of dividends and stock repurchases . we were in compliance with all covenants under the senior credit facility as of december 31 , 2008 . commitments under the senior credit facility are subject to certain fees , including a facility and a utilization fee . the senior credit facility is rated a- by standard & poor 2019s ratings services and is not rated by moody 2019s investors 2019 service , inc . notwithstanding recent interruptions in global credit markets , as of the date of this report , we believe our access to our senior credit facility has not been impaired . in october 2008 , we funded a portion of the acquisition of abbott spine with approximately $ 110 million of new borrowings under the senior credit facility . each of the lenders under the senior credit facility funded its portion of the new borrowings in accordance with its commitment percentage . we also have available uncommitted credit facilities totaling $ 71.4 million . management believes that cash flows from operations , together with available borrowings under the senior credit facility , are sufficient to meet our expected working capital , capital expenditure and debt service needs . should investment opportunities arise , we believe that our earnings , balance sheet and cash flows will allow us to obtain additional capital , if necessary . contractual obligations we have entered into contracts with various third parties in the normal course of business which will require future payments . the following table illustrates our contractual obligations ( in millions ) : contractual obligations total 2009 thereafter .
what percentage of total contractual obligations is due to operating leases?
long-term income taxes payable 116.9 2013 69.6 24.9 22.4 other long-term liabilities 237.0 2013 30.7 15.1 191.2 total contractual obligations $ 1020.1 $ 85.9 $ 158.9 $ 531.8 $ 243.5 critical accounting estimates our financial results are affected by the selection and application of accounting policies and methods . significant accounting policies which require management 2019s judgment are discussed below . excess inventory and instruments 2013 we must determine as of each balance sheet date how much , if any , of our inventory may ultimately prove to be unsaleable or unsaleable at our carrying cost . similarly , we must also determine if instruments on hand will be put to productive use or remain undeployed as a result of excess supply . reserves are established to effectively adjust inventory and instruments to net realizable value . to determine the appropriate level of reserves , we evaluate current stock levels in relation to historical and expected patterns of demand for all of our products and instrument systems and components . the basis for the determination is generally the same for all inventory and instrument items and categories except for work-in-progress inventory , which is recorded at cost . obsolete or discontinued items are generally destroyed and completely written off . management evaluates the need for changes to valuation reserves based on market conditions , competitive offerings and other factors on a regular basis . income taxes 2013 we estimate income tax expense and income tax liabilities and assets by taxable jurisdiction . realization of deferred tax assets in each taxable jurisdiction is dependent on our ability to generate future taxable income sufficient to realize the benefits . we evaluate deferred tax assets on an ongoing basis and provide valuation allowances if it is determined to be 201cmore likely than not 201d that the deferred tax benefit will not be realized . federal income taxes are provided on the portion of the income of foreign subsidiaries that is expected to be remitted to the u.s . we operate within numerous taxing jurisdictions . we are subject to regulatory z i m m e r h o l d i n g s , i n c . 2 0 0 8 f o r m 1 0 - k a n n u a l r e p o r t %%transmsg*** transmitting job : c48761 pcn : 031000000 ***%%pcmsg|31 |00013|yes|no|02/24/2009 06:10|0|0|page is valid , no graphics -- color : d| .