EXHIBIT 12 COMPUTATION OF RATIO OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS (DOLLARS IN THOUSANDS) Three Months ended September 30, Nine Months ended September 30, --------------------------------------- -------------------------------------- 1999 1998 1999 1998 ----------------- ----------------- ----------------- ----------------- Income before extraordinary item $20,042 $13,807 $80,416 $66,071 Add: Portion of rents representative of the interest factor 306 155 795 401 Interest on indebtedness 39,014 27,224 116,011 75,784 ================= ================= ================= ================= Earnings $59,362 $41,186 $197,222 $142,256 ================= ================= ================= ================= Fixed charges and preferred stock dividend: Interest on indebtedness $39,014 $27,224 $116,011 $75,784 Capitalized interest 1,074 910 4,259 2,223 Portion of rents representative of the interest factor 306 155 795 401 ----------------- ----------------- ----------------- ----------------- Fixed charges 40,394 28,289 121,065 78,408 ----------------- ----------------- ----------------- ----------------- Add: Preferred stock dividend 9,441 5,650 28,320 16,953 ----------------- ----------------- ----------------- ----------------- Combined fixed charges and preferred stock dividend $49,835 $33,939 $149,385 $95,361 ================= ================= ================= ================= Ratio of earnings to fixed charges 1.47 x 1.46 x 1.63 x 1.81 x Ratio of earnings to combined fixed charges and preferred stock dividend 1.19 1.21 1.32 1.49