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the fair value of our total investments increased $ 4.8 billion during 2010 , primarily due to unrealized appreciation , the inves- ting of operating cash flows , and the portfolios acquired in the 2010 corporate acquisitions . the following tables show the market value of our fixed maturities and short-term investments at december 31 , 2010 and 2009 . the first table lists investments according to type and the second according to s&p credit rating. .
what is the percentage change in the balance of short-term investments in 2010?
( in millions of u.s . dollars except for percentages ) the short-term investments of 2010 market value is 1983 ; the short-term investments of 2010 percentage of total is 4% ( 4 % ) ; the short-term investments of 2010 market value is 1667 ; the short-term investments of percentageof total is 4% ( 4 % ) ; ( in millions of u.s . dollars except for percentages ) the total of 2010 market value is $ 48983 ; the total of 2010 percentage of total is 100% ( 100 % ) ; the total of 2010 market value is $ 44753 ; the total of percentageof total is 100% ( 100 % ) ;
( in millions of u.s . dollars except for percentages ) 2010 market value 2010 percentage of total 2010 market value percentageof total
treasury $ 2075 4% ( 4 % ) $ 2068 5% ( 5 % )
agency 2015 4% ( 4 % ) 2698 6% ( 6 % )
corporate and asset-backed securities 15900 33% ( 33 % ) 13537 30% ( 30 % )
mortgage-backed securities 12362 25% ( 25 % ) 11311 25% ( 25 % )
municipal 2449 5% ( 5 % ) 2300 5% ( 5 % )
non-u.s . 12199 25% ( 25 % ) 11172 25% ( 25 % )
short-term investments 1983 4% ( 4 % ) 1667 4% ( 4 % )
total $ 48983 100% ( 100 % ) $ 44753 100% ( 100 % )
aaa $ 23718 48% ( 48 % ) $ 22884 51% ( 51 % )
aa 4714 10% ( 10 % ) 4021 9% ( 9 % )
a 8482 17% ( 17 % ) 7461 17% ( 17 % )
bbb 5487 11% ( 11 % ) 4910 11% ( 11 % )
bb 3357 7% ( 7 % ) 2866 6% ( 6 % )
b 2393 5% ( 5 % ) 2029 5% ( 5 % )
other 832 2% ( 2 % ) 582 1% ( 1 % )
total $ 48983 100% ( 100 % ) $ 44753 100% ( 100 % )