EX-12 Computation of Ratio of Earnings to Fixed Charges 1989 1990 1991 1992 1993 (Thousands of Dollars) Fixed Charges, as defined: Interest on long-term debt $ 15,051 14,913 15,120 16,292 16,166 Other interest 2,301 860 1,605 586 596 Interest component of rents charged to operating expenses 274 262 232 214 183 Total Fixed Charges, as defined $ 17,626 16,035 16,957 17,092 16,945 Earnings, as defined: Net income $ 28,627 27,026 29,510 19,217 18,987 Add: Income taxes 18,726 18,527 17,382 9,698 9,464 Fixed charges 17,626 16,035 16,957 17,092 16,945 Total Earnings, as defined $ 64,979 61,588 63,849 46,007 45,396 Ratio of Earnings to Fixed Charges 3.69x 3.84x 3.77x 2.69x 2.68x Computation of Ratio of Earnings to Fixed Charges & Preferred Dividends 1989 1990 1991 1992 1993 (Thousands of Dollars) Fixed Charges, as defined: Interest on long-term debt $ 15,051 14,913 15,120 16,292 16,166 Other interest 2,301 860 1,605 586 596 Interest component of rents charged to operating expenses 274 262 232 214 183 Total Fixed Charges, as defined $ 17,626 16,035 16,957 17,092 16,945 Preferred Dividends, as defined (a) 3,851 3,785 3,438 3,104 3,604 Fixed Charges & Preferred Dividends, as defined $ 21,477 19,820 20,395 20,196 20,549 Earnings, as defined: Net income $ 28,627 27,026 29,510 19,217 18,987 Add: Income taxes 18,726 18,527 17,382 9,698 9,464 Fixed charges 17,626 16,035 16,957 17,092 16,945 Total Earnings, as defined $ 64,979 61,588 63,849 46,007 45,396 Ratio of Earnings to Fixed Charges & Preferred Dividends, as defined 3.03x 3.11x 3.13x 2.28x 2.21x (a) Preferred dividends, as defined (not including preference dividends), have been adjusted by multiplying the requirement by the ratio that income before income taxes bears to net income. Such ratios were as follows: 165% in 1989, 169% in 1990, 159% in 1991, 151% in 1992 and 150% in 1993.