comparable treasury security . the unamortized discount and debt issuance costs are being amortized over the remaining term of the 2022 notes . 2021 notes . in may 2011 , the company issued $ 1.5 billion in aggregate principal amount of unsecured unsubordinated obligations . these notes were issued as two separate series of senior debt securities , including $ 750 million of 4.25% ( 4.25 % ) notes maturing in may 2021 and $ 750 million of floating rate notes ( 201c2013 floating rate notes 201d ) , which were repaid in may 2013 at maturity . net proceeds of this offering were used to fund the repurchase of blackrock 2019s series b preferred from affiliates of merrill lynch & co. , inc . ( 201cmerrill lynch 201d ) . interest on the 4.25% ( 4.25 % ) notes due in 2021 ( 201c2021 notes 201d ) is payable semi-annually on may 24 and november 24 of each year , which commenced november 24 , 2011 , and is approximately $ 32 million per year . the 2021 notes may be redeemed prior to maturity at any time in whole or in part at the option of the company at a 201cmake-whole 201d redemption price . the unamortized discount and debt issuance costs are being amortized over the remaining term of the 2021 notes . 2019 notes . in december 2009 , the company issued $ 2.5 billion in aggregate principal amount of unsecured and unsubordinated obligations . these notes were issued as three separate series of senior debt securities including $ 0.5 billion of 2.25% ( 2.25 % ) notes , which were repaid in december 2012 , $ 1.0 billion of 3.50% ( 3.50 % ) notes , which were repaid in december 2014 at maturity , and $ 1.0 billion of 5.0% ( 5.0 % ) notes maturing in december 2019 ( the 201c2019 notes 201d ) . net proceeds of this offering were used to repay borrowings under the cp program , which was used to finance a portion of the acquisition of barclays global investors ( 201cbgi 201d ) from barclays on december 1 , 2009 ( the 201cbgi transaction 201d ) , and for general corporate purposes . interest on the 2019 notes of approximately $ 50 million per year is payable semi- annually in arrears on june 10 and december 10 of each year . these notes may be redeemed prior to maturity at any time in whole or in part at the option of the company at a 201cmake-whole 201d redemption price . the unamortized discount and debt issuance costs are being amortized over the remaining term of the 2019 notes . 2017 notes . in september 2007 , the company issued $ 700 million in aggregate principal amount of 6.25% ( 6.25 % ) senior unsecured and unsubordinated notes maturing on september 15 , 2017 ( the 201c2017 notes 201d ) . a portion of the net proceeds of the 2017 notes was used to fund the initial cash payment for the acquisition of the fund-of-funds business of quellos and the remainder was used for general corporate purposes . interest is payable semi-annually in arrears on march 15 and september 15 of each year , or approximately $ 44 million per year . the 2017 notes may be redeemed prior to maturity at any time in whole or in part at the option of the company at a 201cmake-whole 201d redemption price . the unamortized discount and debt issuance costs are being amortized over the remaining term of the 2017 notes . 13 . commitments and contingencies operating lease commitments the company leases its primary office spaces under agreements that expire through 2035 . future minimum commitments under these operating leases are as follows : ( in millions ) .
what portion of the total future minimum commitments under operating leases is due in the next 36 months?
rent expense and certain office equipment expense under lease agreements amounted to $ 136 million , $ 132 million and $ 137 million in 2015 , 2014 and 2013 , respectively . investment commitments . at december 31 , 2015 , the company had $ 179 million of various capital commitments to fund sponsored investment funds , including consolidated vies . these funds include private equity funds , real estate funds , infrastructure funds and opportunistic funds . this amount excludes additional commitments made by consolidated funds of funds to underlying third-party funds as third-party noncontrolling interest holders have the legal obligation to fund the respective commitments of such funds of funds . in addition to the capital commitments of $ 179 million , the company had approximately $ 38 million of contingent commitments for certain funds which have investment periods that have expired . generally , the timing of the funding of these commitments is unknown and the commitments are callable on demand at any time prior to the expiration of the commitment . these unfunded commitments are not recorded on the consolidated statements of financial condition . these commitments do not include potential future commitments approved by the company that are not yet legally binding . the company intends to make additional capital commitments from time to time to fund additional investment products for , and with , its clients . contingencies contingent payments . the company acts as the portfolio manager in a series of derivative transactions and has a maximum potential exposure of $ 17 million between the company and counterparty . see note 7 , derivatives and hedging , for further discussion . contingent payments related to business acquisitions . in connection with certain acquisitions , blackrock is required to make contingent payments , subject to the acquired businesses achieving specified performance targets over a certain period subsequent to the applicable acquisition date . the fair value of the remaining aggregate contingent payments at december 31 , 2015 is not significant to the condensed consolidated statement of financial condition and is included in other liabilities. .