what was the net change in the allowance in doubtful accounts in 2009
allowance for doubtful accounts is as follows: .

|  | 2010 | 2009 | 2008 |
| :--- | :--- | :--- | :--- |
| Balance at beginning of year | $160 | $133 | $86 |
| Provision | 38 | 54 | 65 |
| Amounts written off | (13) | (27) | (18) |
| Balance at end of year | $185 | $160 | $133 |

discontinued operations during the fourth quarter of 2009 , schlumberger recorded a net $ 22 million charge related to the resolution of a customs assessment pertaining to its former offshore contract drilling business , as well as the resolution of certain contingencies associated with other previously disposed of businesses . this amount is included in income ( loss ) from discontinued operations in the consolidated statement of income . during the first quarter of 2008 , schlumberger recorded a gain of $ 38 million related to the resolution of a contingency associated with a previously disposed of business . this gain is included in income ( loss ) from discon- tinued operations in the consolidated statement of income . part ii , item 8 .

allowance_change = 54 - 27
answer = allowance_change