state street bank issuances : state street bank currently has authority to issue up to an aggregate of $ 1 billion of subordinated fixed-rate , floating-rate or zero-coupon bank notes with a maturity of five to fifteen years . 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 as tier 2 capital under 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 % ) notes on january 15 and july 15 of each year beginning in july 2006 , 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 beginning in march 2006 . the notes qualify as tier 2 capital under regulatory capital guidelines . note 10 . commitments and contingencies off-balance sheet commitments and contingencies : credit-related financial instruments include indemnified securities financing , unfunded commitments to extend credit or purchase assets and standby letters of credit . the total potential loss on unfunded commitments , standby and commercial letters of credit and securities finance indemnifications is equal to the total contractual amount , which does not consider the value of any collateral . the following is a summary of the contractual amount of credit-related , off-balance sheet financial instruments at december 31 . amounts reported do not reflect participations to unrelated third parties. .
what is the net change in the balance of cash and u.s . government securities held as collateral for indemnified securities on loans in 2006?
on behalf of our customers , we lend their securities to creditworthy brokers and other institutions . in certain circumstances , we may indemnify our customers for the fair market value of those securities against a failure of the borrower to return such securities . collateral funds received in connection with our securities finance services are held by us as agent and are not recorded in our consolidated statement of condition . we require the borrowers to provide collateral in an amount equal to or in excess of 100% ( 100 % ) of the fair market value of the securities borrowed . the borrowed securities are revalued daily to determine if additional collateral is necessary . we held , as agent , cash and u.s . government securities totaling $ 527.37 billion and $ 387.22 billion as collateral for indemnified securities on loan at december 31 , 2006 and 2005 , respectively . approximately 81% ( 81 % ) of the unfunded commitments to extend credit and liquidity asset purchase agreements expire within one year from the date of issue . since many of the commitments are expected to expire or renew without being drawn upon , the total commitment amounts do not necessarily represent future cash requirements . in the normal course of business , we provide liquidity and credit enhancements to asset-backed commercial paper programs , or 201cconduits . 201d these conduits are more fully described in note 11 . the commercial paper issuances and commitments of the conduits to provide funding are supported by liquidity asset purchase agreements and backup liquidity lines of credit , the majority of which are provided by us . in addition , we provide direct credit support to the conduits in the form of standby letters of credit . our commitments under liquidity asset purchase agreements and backup lines of credit totaled $ 23.99 billion at december 31 , 2006 , and are included in the preceding table . our commitments under seq 83 copyarea : 38 . x 54 . trimsize : 8.25 x 10.75 typeset state street corporation serverprocess c:\\fc\\delivery_1024177\\2771-1-dm_p.pdf chksum : 0 cycle 1merrill corporation 07-2771-1 thu mar 01 17:10:46 2007 ( v 2.247w--stp1pae18 ) .