zimmer biomet holdings , inc . 2015 form 10-k annual report through february 25 , 2016 , we repurchased approximately $ 415.0 million of shares of our common stock , which includes the $ 250.0 million of shares that we repurchased from certain selling stockholders on february 10 , 2016 . in order to achieve operational synergies , we expect cash outlays related to our integration plans to be approximately $ 290.0 million in 2016 . these cash outlays are necessary to achieve our integration goals of net annual pre-tax operating profit synergies of $ 350.0 million by the end of the third year post-closing date . also as discussed in note 20 to our consolidated financial statements , as of december 31 , 2015 , a short-term liability of $ 50.0 million and long-term liability of $ 264.6 million related to durom cup product liability claims was recorded on our consolidated balance sheet . we expect to continue paying these claims over the next few years . we expect to be reimbursed a portion of these payments for product liability claims from insurance carriers . as of december 31 , 2015 , we have received a portion of the insurance proceeds we estimate we will recover . we have a long-term receivable of $ 95.3 million remaining for future expected reimbursements from our insurance carriers . we also had a short-term liability of $ 33.4 million related to biomet metal-on-metal hip implant claims . at december 31 , 2015 , we had ten tranches of senior notes outstanding as follows ( dollars in millions ) : principal interest rate maturity date .
what is the $ 500.0 million in principal paid in 2015 as a percentage of the $ 2.5 billion in outstanding borrowings?
we issued $ 7.65 billion of senior notes in march 2015 ( the 201cmerger notes 201d ) , the proceeds of which were used to finance a portion of the cash consideration payable in the biomet merger , pay merger related fees and expenses and pay a portion of biomet 2019s funded debt . on june 24 , 2015 , we also borrowed $ 3.0 billion on a u.s . term loan ( 201cu.s . term loan 201d ) to fund the biomet merger . we may , at our option , redeem our senior notes , in whole or in part , at any time upon payment of the principal , any applicable make-whole premium , and accrued and unpaid interest to the date of redemption . in addition , the merger notes and the 3.375% ( 3.375 % ) senior notes due 2021 may be redeemed at our option without any make-whole premium at specified dates ranging from one month to six months in advance of the scheduled maturity date . we have a $ 4.35 billion credit agreement ( 201ccredit agreement 201d ) that contains : ( i ) a 5-year unsecured u.s . term loan facility ( 201cu.s . term loan facility 201d ) in the principal amount of $ 3.0 billion , and ( ii ) a 5-year unsecured multicurrency revolving facility ( 201cmulticurrency revolving facility 201d ) in the principal amount of $ 1.35 billion . the multicurrency revolving facility will mature in may 2019 , with two one-year extensions available at our option . borrowings under the multicurrency revolving facility may be used for general corporate purposes . there were no borrowings outstanding under the multicurrency revolving facility as of december 31 , 2015 . the u.s . term loan facility will mature in june 2020 , with principal payments due beginning september 30 , 2015 , as follows : $ 75.0 million on a quarterly basis during the first three years , $ 112.5 million on a quarterly basis during the fourth year , and $ 412.5 million on a quarterly basis during the fifth year . in 2015 , we paid $ 500.0 million in principal under the u.s . term loan facility , resulting in $ 2.5 billion in outstanding borrowings as of december 31 , we and certain of our wholly owned foreign subsidiaries are the borrowers under the credit agreement . borrowings under the credit agreement bear interest at floating rates based upon indices determined by the currency of the borrowings plus an applicable margin determined by reference to our senior unsecured long-term credit rating , or at an alternate base rate , or , in the case of borrowings under the multicurrency revolving facility only , at a fixed rate determined through a competitive bid process . the credit agreement 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 consolidated indebtedness to consolidated ebitda ratio of no greater than 5.0 to 1.0 through june 24 , 2016 and no greater than 4.5 to 1.0 thereafter . if our credit rating falls below investment grade , additional restrictions would result , including restrictions on investments and payment of dividends . we were in compliance with all covenants under the credit agreement as of december 31 , 2015 . commitments under the credit agreement are subject to certain fees . on the multicurrency revolving facility , we pay a facility fee at a rate determined by reference to our senior unsecured long-term credit rating . we have a japan term loan agreement with one of the lenders under the credit agreement for 11.7 billion japanese yen that will mature on may 31 , 2018 . borrowings under the japan term loan bear interest at a fixed rate of 0.61 percent per annum until maturity . we also have other available uncommitted credit facilities totaling $ 35.8 million . we place our cash and cash equivalents in highly-rated financial institutions and limit the amount of credit exposure to any one entity . we invest only in high-quality financial instruments in accordance with our internal investment policy . as of december 31 , 2015 , we had short-term and long-term investments in debt securities with a fair value of $ 273.1 million . these investments are in debt securities of many different issuers and , therefore , we believe we have no significant concentration of risk with a single issuer . all of these debt securities remain highly rated and we believe the risk of default by the issuers is low. .