Exhibit 11.1

COMPUTATION OF NET INCOME PER SHARE

(In millions, except share information)

	For the Year Ended						For the Year Ended						For the Year Ended				For the Year Ended				For the Year Ended
	December 31, 2006						December 31, 2005						December 31, 2004				December 31, 2003				December 31, 2002
	Basic			Diluted			Basic			Diluted			Basic		Diluted		Basic		Diluted		Basic			Diluted
Income (loss) before cumulative effect of a change in accounting principle	$	(710.4	)	$	(710.4	)	$	(1,381.5	)	$	(1,381.5	)	$	422.2	$	422.2	$	380.5	$	380.5	$	311.5		$	311.5
After-tax interest expense on convertible debt		—			—			—			—			—		9.3		—		9.0		—			7.4
Income (loss) before cumulative effect of a change in accounting principle, for diluted net income (loss) per share		(710.4	)		(710.4	)		(1,381.5	)		(1,381.5	)		422.2		431.5		380.5		389.5		311.5			318.9
Cumulative effect of a change in accounting principle, net of tax		2.9			2.9			—			—			—		—		—		—		(298.5	)		(298.5	)
Net income (loss), for diluted net income (loss) per share	$	(707.5	)	$	(707.5	)	$	(1,381.5	)	$	(1,381.5	)	$	422.2	$	431.5	$	380.5	$	389.5	$	13.0		$	20.4
Weighted average shares:
Common shares outstanding		68,607,262			68,607,262			67,166,668			67,166,668			68,278,858		68,278,858		66,689,757		66,689,757		65,365,218			65,365,218
Exercise of stock options (1)		—			—			—			—			—		1,635,349		—		1,843,755		—			1,691,921
Exercise of warrants (2)		—			—			—			—			—		—		—		—		—			—
Shares issuable upon conversion of convertible debt (3)		—			—			—			—			—		4,813,056		—		4,813,056		—			4,232,852
Common and equivalent shares outstanding		68,607,262			68,607,262			67,166,668			67,166,668			68,278,858		74,727,263		66,689,757		73,346,568		65,365,218			71,289,991
Per common and equivalent share:
Income (loss) before cumulative effect of a change in accounting principle	$	(10.35	)	$	(10.35	)	$	(20.57	)	$	(20.57	)	$	6.18	$	5.77	$	5.71	$	5.31	$	4.77		$	4.47
Cumulative effect of a change in accounting principle		0.04			0.04			—			—			—		—		—		—		(4.57	)		(4.18	)
Net income (loss)	$	(10.31	)	$	(10.31	)	$	(20.57	)	$	(20.57	)	$	6.18	$	5.77	$	5.71	$	5.31	$	0.20		$	0.29

(1)	Amount represents the number of common shares issued assuming exercise of stock options outstanding, reduced by the number of shares which could have been purchased with the proceeds from the exercise of such options.
(2)	Amount represents the number of common shares issued assuming exercise of warrants outstanding.
(3)	Amount represents the number of common shares issued assuming the conversion of convertible debt outstanding.