EXHIBIT 12 Statement of Computation of Ratio of Earnings to Fixed Charges As Pro Adjusted Forma 6 months (000's) 1995 1996 1997 1998 1999 1999 1999 3/31/00 - ----------------------------------------------------------------------------------------------------------------------------------- Earnings: Pretax Income 1,586 3,725 33,169 59,579 103,890 103,890 27,643 29,966 Fixed Charges: Interest expense on convertible subordinated debentures 24,000 24,000 1,425 Interest in operating leases 215 251 240 390 460 460 462 218 Interest expense as recorded 1,304 772 161 76 52 52 62 184 ------------------------------------------------------------------------ Subtotal Earnings 3,105 4,748 33,570 60,045 104,402 128,402 52,167 31,793 Fixed Charges: Interest expense on convertible subordinated debentures 24,000 24,000 1,425 Interest in operating leases 215 251 240 390 460 460 462 218 Interest expense as recorded 1,304 772 161 76 52 52 62 184 ------------------------------------------------------------------------ 1,519 1,023 401 466 512 24,512 24,524 402 2.04 14.42 83.72 128.85 203.91 5.24 2.13 79.01 ------------------------------------------------------------------------ As Adjusted Pro Forma 6 months 6 months (000'0) 3/31/00 3/31/00 - ----------------------------------------------------------------------------------------- Earnings: Pretax Income 29,966 33,864 Fixed Charges: Interest expense on convertible subordinated debentures 14,400 14,400 Interest in operating leases 218 219 Interest expense as recorded 184 194 ----------------------------- Subtotal Earnings 44,768 48,677 Fixed Charges: Interest expense on debentures 14,400 14,400 Interest in operating leases 218 219 Interest expense as recorded 184 194 ----------------------------- 14,802 14,813 ----------------------------- 6.78 6.78 -----------------------------