Exhibit 12.1

Computation of Ratio of Earnings to Fixed Charges

			Twelve Months Ended December 31,
	Six Months Ended
	June 30, 2002		2001			2000		1999		1998		1997
Income (Loss) before income taxes, extraordinary item and cumulative effect of accounting changes	$	22,361	$	(26,883	)	$	70,597	$	98,991	$	185,350	$	266,592
Amortization of capitalized interest		1,450		2,810			2,444		2,432		2,437		2,213
Interest expense		15,924		33,401			31,922		27,225		26,502		21,432
Interest portion of rental expense		749		2,585			3,254		3,401		3,260		3,267
Earnings	$	40,484	$	11,913		$	108,217	$	132,049	$	217,549	$	293,504
Interest	$	16,107	$	34,824		$	33,276	$	30,877	$	31,265	$	23,608
Interest portion of rental expense		749		2,111			3,254		3,401		3,260		3,267
Fixed Charges	$	16,856	$	36,935		$	36,530	$	34,278	$	34,525	$	26,875
Ratio of Earnings to Fixed Charges		2.40		(1	)		2.96		3.85		6 .30		10.92

(1)  Earnings were inadequate to cover fixed charges for the twelve-month period ended December 31, 2001. The coverage deficiency totaled $25,022,000 for that period.