the fair value of the interest agreements at december 31 , 2007 and december 31 , 2006 was $ 3 million and $ 1 million , respectively . the company is exposed to credit loss in the event of nonperformance by the counterparties to its swap contracts . the company minimizes its credit risk on these transactions by only dealing with leading , creditworthy financial institutions and does not anticipate nonperformance . in addition , the contracts are distributed among several financial institutions , all of whom presently have investment grade credit ratings , thus minimizing credit risk concentration . stockholders 2019 equity derivative instruments activity , net of tax , included in non-owner changes to equity within the consolidated statements of stockholders 2019 equity for the years ended december 31 , 2007 and 2006 is as follows: .
what is the percent change in increase of fair value between 2005 and 2006?
net investment in foreign operations hedge at december 31 , 2007 and 2006 , the company did not have any hedges of foreign currency exposure of net investments in foreign operations . investments hedge during the first quarter of 2006 , the company entered into a zero-cost collar derivative ( the 201csprint nextel derivative 201d ) to protect itself economically against price fluctuations in its 37.6 million shares of sprint nextel corporation ( 201csprint nextel 201d ) non-voting common stock . during the second quarter of 2006 , as a result of sprint nextel 2019s spin-off of embarq corporation through a dividend to sprint nextel shareholders , the company received approximately 1.9 million shares of embarq corporation . the floor and ceiling prices of the sprint nextel derivative were adjusted accordingly . the sprint nextel derivative was not designated as a hedge under the provisions of sfas no . 133 , 201caccounting for derivative instruments and hedging activities . 201d accordingly , to reflect the change in fair value of the sprint nextel derivative , the company recorded a net gain of $ 99 million for the year ended december 31 , 2006 , included in other income ( expense ) in the company 2019s consolidated statements of operations . in december 2006 , the sprint nextel derivative was terminated and settled in cash and the 37.6 million shares of sprint nextel were converted to common shares and sold . the company received aggregate cash proceeds of approximately $ 820 million from the settlement of the sprint nextel derivative and the subsequent sale of the 37.6 million sprint nextel shares . the company recognized a loss of $ 126 million in connection with the sale of the remaining shares of sprint nextel common stock . as described above , the company recorded a net gain of $ 99 million in connection with the sprint nextel derivative . prior to the merger of sprint corporation ( 201csprint 201d ) and nextel communications , inc . ( 201cnextel 201d ) , the company had entered into variable share forward purchase agreements ( the 201cvariable forwards 201d ) to hedge its nextel common stock . the company did not designate the variable forwards as a hedge of the sprint nextel shares received as a result of the merger . accordingly , the company recorded $ 51 million of gains for the year ended december 31 , 2005 reflecting the change in value of the variable forwards . the variable forwards were settled during the fourth quarter of 2005 . fair value of financial instruments the company 2019s financial instruments include cash equivalents , sigma fund investments , short-term investments , accounts receivable , long-term finance receivables , accounts payable , accrued liabilities , derivatives and other financing commitments . the company 2019s sigma fund and investment portfolios and derivatives are recorded in the company 2019s consolidated balance sheets at fair value . all other financial instruments , with the exception of long-term debt , are carried at cost , which is not materially different than the instruments 2019 fair values. .