our non-operating investment activity resulted in net losses of $ 12.7 million in 2009 and $ 52.3 million in 2008 .the improvement of nearly $ 40 million is primarily attributable to a reduction in the other than temporary impairments recognized on our investments in sponsored mutual funds in 2009 versus 2008 .the following table details our related mutual fund investment gains and losses ( in millions ) during the past two years. .
[['', '2008', '2009', 'change'], ['other than temporary impairments recognized', '$ -91.3 ( 91.3 )', '$ -36.1 ( 36.1 )', '$ 55.2'], ['capital gain distributions received', '5.6', '2.0', '-3.6 ( 3.6 )'], ['net gain ( loss ) realized on fund dispositions', '-4.5 ( 4.5 )', '7.4', '11.9'], ['net loss recognized on fund holdings', '$ -90.2 ( 90.2 )', '$ -26.7 ( 26.7 )', '$ 63.5']]
lower income of $ 16 million from our money market holdings due to the significantly lower interest rate environment offset the improvement experienced with our fund investments .there is no impairment of any of our mutual fund investments at december 31 , 2009 .the 2009 provision for income taxes as a percentage of pretax income is 37.1% ( 37.1 % ) , down from 38.4% ( 38.4 % ) in 2008 and .9% ( .9 % ) lower than our present estimate of 38.0% ( 38.0 % ) for the 2010 effective tax rate .our 2009 provision includes reductions of prior years 2019 tax provisions and discrete nonrecurring benefits that lowered our 2009 effective tax rate by 1.0% ( 1.0 % ) .2008 versus 2007 .investment advisory revenues decreased 6.3% ( 6.3 % ) , or $ 118 million , to $ 1.76 billion in 2008 as average assets under our management decreased $ 16 billion to $ 358.2 billion .the average annualized fee rate earned on our assets under management was 49.2 basis points in 2008 , down from the 50.2 basis points earned in 2007 , as lower equity market valuations resulted in a greater percentage of our assets under management being attributable to lower fee fixed income portfolios .continuing stress on the financial markets and resulting lower equity valuations as 2008 progressed resulted in lower average assets under our management , lower investment advisory fees and lower net income as compared to prior periods .net revenues decreased 5% ( 5 % ) , or $ 112 million , to $ 2.12 billion .operating expenses were $ 1.27 billion in 2008 , up 2.9% ( 2.9 % ) or $ 36 million from 2007 .net operating income for 2008 decreased $ 147.9 million , or 14.8% ( 14.8 % ) , to $ 848.5 million .higher operating expenses in 2008 and decreased market valuations during the latter half of 2008 , which lowered our assets under management and advisory revenues , resulted in our 2008 operating margin declining to 40.1% ( 40.1 % ) from 44.7% ( 44.7 % ) in 2007 .non-operating investment losses in 2008 were $ 52.3 million as compared to investment income of $ 80.4 million in 2007 .investment losses in 2008 include non-cash charges of $ 91.3 million for the other than temporary impairment of certain of the firm 2019s investments in sponsored mutual funds .net income in 2008 fell 27% ( 27 % ) or nearly $ 180 million from 2007 .diluted earnings per share , after the retrospective application of new accounting guidance effective in 2009 , decreased to $ 1.81 , down $ .59 or 24.6% ( 24.6 % ) from $ 2.40 in 2007 .a non-operating charge to recognize other than temporary impairments of our sponsored mutual fund investments reduced diluted earnings per share by $ .21 in 2008 .investment advisory revenues earned from the t .rowe price mutual funds distributed in the united states decreased 8.5% ( 8.5 % ) , or $ 114.5 million , to $ 1.24 billion .average mutual fund assets were $ 216.1 billion in 2008 , down $ 16.7 billion from 2007 .mutual fund assets at december 31 , 2008 , were $ 164.4 billion , down $ 81.6 billion from the end of 2007 .net inflows to the mutual funds during 2008 were $ 3.9 billion , including $ 1.9 billion to the money funds , $ 1.1 billion to the bond funds , and $ .9 billion to the stock funds .the value , equity index 500 , and emerging markets stock funds combined to add $ 4.1 billion , while the mid-cap growth and equity income stock funds had net redemptions of $ 2.2 billion .net fund inflows of $ 6.2 billion originated in our target-date retirement funds , which in turn invest in other t .rowe price funds .fund net inflow amounts in 2008 are presented net of $ 1.3 billion that was transferred to target-date trusts from the retirement funds during the year .decreases in market valuations and income not reinvested lowered our mutual fund assets under management by $ 85.5 billion during 2008 .investment advisory revenues earned on the other investment portfolios that we manage decreased $ 3.6 million to $ 522.2 million .average assets in these portfolios were $ 142.1 billion during 2008 , up slightly from $ 141.4 billion in 2007 .these minor changes , each less than 1% ( 1 % ) , are attributable to the timing of declining equity market valuations and cash flows among our separate account and subadvised portfolios .net inflows , primarily from institutional investors , were $ 13.2 billion during 2008 , including the $ 1.3 billion transferred from the retirement funds to target-date trusts .decreases in market valuations , net of income , lowered our assets under management in these portfolios by $ 55.3 billion during 2008 .management 2019s discussion & analysis 21 .

Question: what percentage of the net inflows primarily from institutional investors was due to the transfer from retirement funds to target-date trusts?
Answer: 10%