25. COMPENSATION, DEPRECIATION AND AMORTIZATION EXPENSES  26. INCOME TAX  The balances of income tax payable as of December 31, 2008, 2009 and 2010 were shown net of prepaid  income tax.  a. The components of income taxes are as follows:  b. A reconciliation between income tax expense computed by applying the statutory income tax rate of 25%  for 2008 and 2009, and 17% for 2010 to income before income tax and income tax expense shown in the  statements of income and comprehensive income is as follows:  c. Income tax expense consisted of following:  F-43 Year Ended December 31 2008 2009  2010 NT$ NT$ NT$ (In Millions) Income tax expense computed at statutory tax rate $  15,026  $  14,404  $  9,912  Permanent differences (144) (188) (188) Investment tax credits (1,505) (1,425) (602) 10% undistributed earning tax 2  7  5  Prior year adjustment 78  (196) (2) Other 435  141  4  Income tax expense $  13,892  $  12,743  $  9,129  Year Ended December 31 2008 2009 2010 NT$ NT$ NT$ (In Millions) Current $  14,048  $  11,644  $  9,102  Deferred (156) 1,099  27  $  13,892  $  12,743  $  9,129  Year Ended December 31, 2009 Operating  Costs Operating  Expenses Total NT$ NT$ NT$ (In Millions) Compensation expense Salaries  $  12,544  $  9,901  $  22,445  Insurance  999  771  1,770  Pension  1,517  1,138  2,655  Other compensation  8,807  6,031  14,838  $  23,867  $  17,841  $  41,708  Depreciation expense  33,169  1,945  35,114  Amortization expense  $  957  $  232  $  1,189  Year Ended December 31, 2010 Operating  Costs Operating  Expenses Total NT$ NT$ NT$ (In Millions) Compensation expense Salaries $  12,616  $  10,313  $  22,929  Insurance 1,053  828  1,881  Pension 1,705  1,203  2,908  Other compensation 9,652  6,705  16,357  $  25,026  $  19,049  $  44,075  Depreciation expense 30,972  1,765  32,737  Amortization expense $  1,087  $  222  $  1,309 