EXHIBIT NO. 12 COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES AND PREFERRED DIVIDENDS COMBINED AND RATIO OF EARNINGS TO FIXED CHARGES ------------------------------------------------------ Years Ended December 31, ------------------------------------------------------ 1998 1997 1996 1995 1994 ---- ---- ---- ---- ---- (Thousands of Dollars) Earnings, as defined: Net income $ 399,238 $388,317 $ 391,277 $ 372,604 $ 313,167 Fixed charges, as below 191,832 193,632 204,593 226,833 213,821 Income taxes, as below 249,180 225,340 247,405 232,046 180,518 ----------- --------- ---------- ---------- ---------- Total earnings, as defined $ 840,250 $807,289 $ 843,275 $ 831,483 $ 707,506 =========== ========= ========== ========== ========== Fixed Charges, as defined: Interest on long-term debt $ 169,901 $163,468 $ 172,622 $ 187,397 $ 183,891 Other interest 11,156 18,743 19,155 25,896 16,119 Imputed interest factor in rentals-charged principally to operating expenses 10,775 11,421 12,816 13,540 13,811 ----------- --------- ---------- ---------- ---------- Total fixed charges, as defined $ 191,832 $ 193,632 $ 204,593 $ 226,833 $ 213,821 =========== ========= ========== ========== ========== Earnings Before Income Taxes $ 648,418 $613,657 $ 638,682 $ 604,650 $ 493,685 =========== ========= ========== ========== ========== Ratio of Earnings Before Income Taxes to Net Income 1.62 1.58 1.63 1.62 1.58 Income Taxes: Income tax expense 257,494 233,565 255,630 240,386 188,813 Included in AFUDC - deferred taxes in nuclear fuel amortization and book depreciation (8,314) (8,225) (8,225) (8,340) (8,295) ----------- --------- ---------- ---------- ---------- Total income taxes $ 249,180 $ 225,340 $ 247,405 $ 232,046 $ 180,518 =========== ========= ========== ========== ========== Fixed Charges and Preferred Dividends Combined: Preferred dividend requirements $ 2,967 $ 6,052 $ 9,609 $ 9,609 $ 9,609 Portion deductible for income tax purposes (312) (312) (312) (312) (312) ----------- --------- ---------- ---------- ---------- Preferred dividend requirements not deductible $ 2,655 $ 5,740 $ 9,297 $ 9,297 $ 9,297 =========== ========= ========== ========== ========== Preferred dividend factor: Preferred dividends not deductible times ratio of earnings before income taxes to net income $ 4,301 $ 9,069 $ 15,154 $ 15,061 $ 14,689 Preferred dividends deductible for income taxes 312 312 312 312 312 Fixed charges, as above 191,832 193,632 204,593 226,833 213,821 ----------- --------- ---------- ---------- ---------- Total fixed charges and preferred dividends combined $ 196,445 $203,013 $ 220,059 $ 242,206 $ 228,822 =========== ========= ========== ========== ========== Ratio of Earnings to Fixed Charges and Preferred Dividends Combined 4.28 3.98 3.83 3.43 3.09 Ratio of Earnings to Fixed Charges 4.38 4.17 4.12 3.67 3.31