Mortgage banking revenue consists of the following: At December 31, 2002, 2001 and 2000, TCF was servicing real estate loans for others with aggregate unpaid principal balances of approximately $5.6 billion, $4.7 billion and $4 billion, respectively. During 2000, TCF purchased the bulk servicing rights on $933 mil- lion of residential mortgage loans at a cost of $13.8 million. No bulk servicing rights were purchased during 2002 or 2001. No bulk ser- vicing rights were sold during 2002, 2001 or 2000. At December 31, 2002, and 2001, TCF had custodial funds of $287.4 million and $219.1 million, respectively, relating to the servicing of residen- tial real estate loans, which are included in deposits in the Consolidated Statements of Financial Condition. These custodial The estimated fair value of mortgage servicing rights included in the Consolidated Statements of Financial Condition at December 31, 2002 was approximately $62.6 million. The estimated fair value of capitalized mortgage servicing rights is based on estimated cash flows discounted using rates management believes are commensurate with the risks involved. Assumptions regarding prepayments, defaults and interest rates are determined using available market information.  deposits relate primarily to mortgage servicing operations and rep- resent customer funds for taxes and insurance and funds due investors on mortgage loans serviced by TCF.  page 59 11. Deposits Deposits are summarized as follows:  At December 31, 2002 2001 Weighted- Weighted- Average % of Average % of (Dollars in thousands) Rate Amount Total Rate Amount Total Checking: Non-interest bearing . . . . . . . . . . . . –% $1,879,584 24.4% –% $1,664,403 23.4% Interest bearing . . . . . . . . . . . . . . . . .12 985,312 12.8 .20 872,462 12.3 .04 2,864,896  37.2 .07 2,536,865 35.7 Savings: Non-interest bearing . . . . . . . . . . . . – 228,210  2.9 – 169,527 2.4 Interest bearing . . . . . . . . . . . . . . . . .90 1,813,513  23.5 .61 1,121,289 15.8 .80 2,041,723  26.4 .53 1,290,816 18.2 Money market . . . . . . . . . . . . . . . . . . . . .74 884,614 11.5 1.20 951,033 13.4 Total checking, savings and money market . . . . . . . . . . . . . . . .42 5,791,233 75.1 .42 4,778,714 67.3 Certificates . . . . . . . . . . . . . . . . . . . . . . 2.85 1,918,755 24.9 3.71 2,320,244 32.7 1.02 $7,709,988 100.0% 1.49 $7,098,958 100.0% Year Ended December 31, (Dollars in thousands) 2002 2001 2000 Servicing income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 20,443  $ 16,932 $ 12,642 Less mortgage servicing: Amortization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22,874  16,564 5,326 Impairment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12,500  4,400 – Subtotal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35,374  20,964 5,326 Net servicing income (loss) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (14,931) (4,032) 7,316 Gains on sales of loans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18,110  11,795 1,347 Other income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,800  4,279 1,856 Total mortgage banking revenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 6,979  $ 12,042 $ 10,519