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Exhibit 12.1

COMPUTATIONS OF RATIO OF EARNINGS TO FIXED CHARGES

		Year ended December 31,														Three months ended March 31,
		2000			2001		2002			2003			2004			2004			2005
		(dollars in millions)
Earnings:
Income (loss) before income taxes		$	209.4		$	228.5	$	(1,049.8	)	$	291.2		$	(9.2	)	$	176.2		$	175.6
Loss related to equity method investees			—			—		0.1			0.6			—			—			—
			209.4			228.5		(1,049.7	)		291.8			(9.2	)		176.2			175.6
Add/(deduct):
	Fixed charges		1.9			1.3		13.0			16.9			14.1			4.9			3.0
	Amortization of capitalized interest		0.1			0.2		0.2			0.2			0.3			—			—
	Interest costs capitalized		(0.3	)		—		(0.9	)		(2.9	)		(1.6	)		(0.8	)		(0.3	)
Earnings available for fixed charges		$	211.1		$	230.0	$	(1,037.4	)	$	306.0		$	3.6		$	180.3		$	178.3
Fixed charges:
	Interest expense(1)	$	0.8		$	0.6	$	10.0		$	13.8		$	11.0		$	4.0		$	2.3
	Interest portion of rental expense(2)		1.1			0.7		3.0			3.1			3.1			0.9			0.7
Total fixed charges		$	1.9		$	1.3	$	13.0		$	16.9		$	14.1		$	4.9		$	3.0
Ratio of earnings to fixed charges			112			174					18			—			37			60
Deficiency of earnings to fixed charges			—			—	$	(1,050.4	)		—			(10.5	)

(1)

Includes interest, whether expensed or capitalized, and amortization of debt expense and premium relating to indebtedness.

(2)

One-third of all rental expense is deemed to be interest.

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Exhibit 12.1

COMPUTATIONS OF RATIO OF EARNINGS TO FIXED CHARGES