management 2019s discussion and analysis 144 jpmorgan chase & co./2010 annual report compared with $ 57 million for 2009 . decreases in cio and mort- gage banking var for 2010 were again driven by the decline in market volatility and position changes . the decline in mortgage banking var at december 31 , 2010 , reflects management 2019s deci- sion to reduce risk given market volatility at the time . the firm 2019s average ib and other var diversification benefit was $ 59 million or 37% ( 37 % ) of the sum for 2010 , compared with $ 82 million or 28% ( 28 % ) of the sum for 2009 . the firm experienced an increase in the diversification benefit in 2010 as positions changed and correla- tions decreased . in general , over the course of the year , var expo- sure can vary significantly as positions change , market volatility fluctuates and diversification benefits change . var back-testing the firm conducts daily back-testing of var against its market risk- related revenue , which is defined as the change in value of : princi- pal transactions revenue for ib and cio ( less private equity gains/losses and revenue from longer-term cio investments ) ; trading-related net interest income for ib , cio and mortgage bank- ing ; ib brokerage commissions , underwriting fees or other revenue ; revenue from syndicated lending facilities that the firm intends to distribute ; and mortgage fees and related income for the firm 2019s mortgage pipeline and warehouse loans , msrs , and all related hedges . daily firmwide market risk 2013related revenue excludes gains and losses from dva . the following histogram illustrates the daily market risk 2013related gains and losses for ib , cio and mortgage banking positions for 2010 . the chart shows that the firm posted market risk 2013related gains on 248 out of 261 days in this period , with 12 days exceeding $ 210 million . the inset graph looks at those days on which the firm experienced losses and depicts the amount by which the 95% ( 95 % ) confidence-level var ex- ceeded the actual loss on each of those days . during 2010 , losses were sustained on 13 days , none of which exceeded the var measure . daily ib and other market risk-related gains and losses ( 95% ( 95 % ) confidence-level var ) year ended december 31 , 2010 average daily revenue : $ 87 million $ in millions $ in millions daily ib and other var less market risk-related losses the following table provides information about the gross sensitivity of dva to a one-basis-point increase in jpmorgan chase 2019s credit spreads . this sensitivity represents the impact from a one-basis-point parallel shift in jpmorgan chase 2019s entire credit curve . as credit curves do not typically move in a parallel fashion , the sensitivity multiplied by the change in spreads at a single maturity point may not be representative of the actual revenue recognized . debit valuation adjustment sensitivity 1 basis point increase in december 31 , ( in millions ) jpmorgan chase 2019s credit spread .

Table:
december 31 ( in millions ) | 1 basis point increase in jpmorgan chase 2019s credit spread
2010 | $ 35
2009 | $ 39
.

Question: what was the change in average ib and other var diversification benefit in millions during 2010?
Answer: -23
Calculation: subtract(59, 82)