investments prior to our acquisition of keystone on october 12 , 2007 , we held common shares of keystone , which were classified as an available-for-sale investment security . accordingly , the investment was included in other assets at its fair value , with the unrealized gain excluded from earnings and included in accumulated other comprehensive income , net of applicable taxes . upon our acquisition of keystone on october 12 , 2007 , the unrealized gain was removed from accumulated other comprehensive income , net of applicable taxes , and the original cost of the common shares was considered a component of the purchase price . fair value of financial instruments our debt is reflected on the balance sheet at cost . based on current market conditions , our interest rate margins are below the rate available in the market , which causes the fair value of our debt to fall below the carrying value . the fair value of our term loans ( see note 6 , 201clong-term obligations 201d ) is approximately $ 570 million at december 31 , 2009 , as compared to the carrying value of $ 596 million . we estimated the fair value of our term loans by calculating the upfront cash payment a market participant would require to assume our obligations . the upfront cash payment , excluding any issuance costs , is the amount that a market participant would be able to lend at december 31 , 2009 to an entity with a credit rating similar to ours and achieve sufficient cash inflows to cover the scheduled cash outflows under our term loans . the carrying amounts of our cash and equivalents , net trade receivables and accounts payable approximate fair value . we apply the market approach to value our financial assets and liabilities , which include the cash surrender value of life insurance , deferred compensation liabilities and interest rate swaps . the market approach utilizes available market information to estimate fair value . required fair value disclosures are included in note 8 , 201cfair value measurements . 201d accrued expenses we self-insure a portion of employee medical benefits under the terms of our employee health insurance program . we purchase certain stop-loss insurance to limit our liability exposure . we also self-insure a portion of our property and casualty risk , which includes automobile liability , general liability , workers 2019 compensation and property under deductible insurance programs . the insurance premium costs are expensed over the contract periods . a reserve for liabilities associated with these losses is established for claims filed and claims incurred but not yet reported based upon our estimate of ultimate cost , which is calculated using analyses of historical data . we monitor new claims and claim development as well as trends related to the claims incurred but not reported in order to assess the adequacy of our insurance reserves . self-insurance reserves on the consolidated balance sheets are net of claims deposits of $ 0.7 million and $ 0.8 million , at december 31 , 2009 and 2008 , respectively . while we do not expect the amounts ultimately paid to differ significantly from our estimates , our insurance reserves and corresponding expenses could be affected if future claim experience differs significantly from historical trends and assumptions . product warranties some of our mechanical products are sold with a standard six-month warranty against defects . we record the estimated warranty costs at the time of sale using historical warranty claim information to project future warranty claims activity and related expenses . the changes in the warranty reserve are as follows ( in thousands ) : .

Table: balance as of january 1 2008 $ 580 warranty expense 3681 warranty claims -3721 ( 3721 ) balance as of december 31 2008 540 warranty expense 5033 warranty claims -4969 ( 4969 ) balance as of december 31 2009 $ 604

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Question: what was the percentage change in warranty reserves from 2008 to 2009?
Answer: 12%
Calculation: divide(subtract(604, 540), 540)