EXHIBIT NO. 12 COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES AND PREFERRED DIVIDENDS COMBINED AND RATIO OF EARNINGS TO FIXED CHARGES ------------------------- --------------------------------------------------- 12 Months Ended June 30, Years Ended December 31, ------------------------- --------------------------------------------------- 1999 1998 1998 1997 1996 1995 1994 ---- ---- ---- ---- ---- ---- ---- (Thousands of Dollars) Earnings, as defined: Net income $ 402,569 $403,805 $399,238 $388,317 $ 391,277 $372,604 $313,167 Fixed charges, as below 192,281 193,680 191,832 193,632 204,593 226,833 213,821 Income taxes, as below 243,499 253,325 249,180 225,340 247,405 232,046 180,518 ------------------------------------------------------------------------------- Total earnings, as defined $ 838,349 $850,810 $840,250 $807,289 $ 843,275 $831,483 $ 707,506 =============================================================================== Fixed Charges, as defined: Interest on long-term debt $ 169,475 $169,140 $169,901 $163,468 $ 172,622 $ 187,397 $ 183,891 Other interest 11,630 13,755 11,156 18,743 19,155 25,896 16,119 Imputed interest factor in rentals-charged Principally to operating expenses 11,176 10,785 10,775 11,421 12,816 13,540 13,811 ------------------------------------------------------------------------------- Total fixed charges, as defined $ 192,281 $193,680 $191,832 $ 193,632 $ 204,593 $226,833 $213,821 =============================================================================== Earnings Before Income Taxes $ 646,068 $657,130 $648,418 $613,657 $ 638,682 $604,650 $493,685 =============================================================================== Ratio of Earnings Before Income Taxes to Net Income 1.60 1.63 1.62 1.58 1.63 1.62 1.58 Income Taxes: Income tax expense 255,195 261,595 257,494 233,565 255,630 240,386 188,813 Included in AFUDC - deferred taxes in nuclear Fuel amortization and book depreciation (11,696) (8,270) (8,314) (8,225) (8,225) (8,340) (8,295) ------------------------------------------------------------------------------- Total income taxes $ 243,499 $253,325 $249,180 $225,340 $ 247,405 $232,046 $180,518 =============================================================================== Fixed Charges and Preferred Dividends Combined: Preferred dividend requirements $ 2,968 $ 4,391 $ 2,967 $ 6,052 $ 9,609 $ 9,609 $ 9,609 Portion deductible for income tax purposes (312) (312) (312) (312) (312) (312) (312) ------------------------------------------------------------------------------- Preferred dividend requirements not deductible $ 2,656 $ 4,079 $ 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 $ 4,250 $ 6,649 $ 4,301 $ 9,069 $ 15,154 $ 15,061 $ 14,689 Preferred dividends deductible for income taxes 312 312 312 312 312 312 312 Fixed charges, as above 192,281 193,680 191,832 193,632 204,593 226,833 213,821 ------------------------------------------------------------------------------- Total fixed charges and preferred dividends combined $ 196,843 $200,641 $196,445 $203,013 $ 220,059 $ 242,206 $228,822 =============================================================================== Ratio of Earnings to Fixed Charges and Preferred Dividends Combined 4.26 4.24 4.28 3.98 3.83 3.43 3.09 Ratio of Earnings to Fixed Charges 4.36 4.39 4.38 4.17 4.12 3.67 3.31