state street corporation notes to consolidated financial statements ( continued ) with respect to the 5.25% ( 5.25 % ) subordinated bank notes due 2018 , state street bank is required to make semi- annual interest payments on the outstanding principal balance of the notes on april 15 and october 15 of each year , and the notes qualify for inclusion in tier 2 regulatory capital under current federal regulatory capital guidelines . with respect to the 5.30% ( 5.30 % ) subordinated notes due 2016 and the floating-rate subordinated notes due 2015 , state street bank is required to make semi-annual interest payments on the outstanding principal balance of the 5.30% ( 5.30 % ) subordinated notes on january 15 and july 15 of each year , and quarterly interest payments on the outstanding principal balance of the floating-rate notes on march 8 , june 8 , september 8 and december 8 of each year . each of the subordinated notes qualifies for inclusion in tier 2 regulatory capital under current federal regulatory capital guidelines . note 11 . commitments , guarantees and contingencies commitments : we had unfunded off-balance sheet commitments to extend credit totaling $ 21.30 billion and $ 17.86 billion as of december 31 , 2013 and 2012 , respectively . the potential losses associated with these commitments equal the gross contractual amounts , and do not consider the value of any collateral . approximately 75% ( 75 % ) of our unfunded commitments to extend credit expire within one year from the date of issue . since many of these commitments are expected to expire or renew without being drawn upon , the gross contractual amounts do not necessarily represent our future cash requirements . guarantees : off-balance sheet guarantees are composed of indemnified securities financing , stable value protection , unfunded commitments to purchase assets , and standby letters of credit . the potential losses associated with these guarantees equal the gross contractual amounts , and do not consider the value of any collateral . the following table presents the aggregate gross contractual amounts of our off-balance sheet guarantees as of december 31 , 2013 and 2012 . amounts presented do not reflect participations to independent third parties. .
what is the percentage change in the balance of asset purchase agreements from 2012 to 2013?
indemnified securities financing on behalf of our clients , we lend their securities , as agent , to brokers and other institutions . in most circumstances , we indemnify our clients for the fair market value of those securities against a failure of the borrower to return such securities . we require the borrowers to maintain collateral in an amount equal to or in excess of 100% ( 100 % ) of the fair market value of the securities borrowed . securities on loan and the collateral are revalued daily to determine if additional collateral is necessary or if excess collateral is required to be returned to the borrower . collateral received in connection with our securities lending services is held by us as agent and is not recorded in our consolidated statement of condition . the cash collateral held by us as agent is invested on behalf of our clients . in certain cases , the cash collateral is invested in third-party repurchase agreements , for which we indemnify the client against loss of the principal invested . we require the counterparty to the indemnified repurchase agreement to provide collateral in an amount equal to or in excess of 100% ( 100 % ) of the amount of the repurchase agreement . in our role as agent , the indemnified repurchase agreements and the related collateral held by us are not recorded in our consolidated statement of condition. .