Exhibit 12.1

CALCULATION OF RATIO OF EARNINGS TO FIXED CHARGES

															Six Months Ended
	Year Ended December 31,														June 30,
	2002		2003			2004			2005			2006			2006			2007
	(dollars in thousands)
Earnings available for fixed charges:
Income before income taxes	$	155,833	$	31,657		$	111,890		$	326,102		$	90,523		$	69,104		$	157,753
Fixed charges		27,393		58,594			70,724			114,965			202,074			79,085			142,112
Amortization of capitalized interest		—		—			90			408			843			326			753
Capitalized interest		—		(127	)		(2,919	)		(3,564	)		(17,503	)		(4,045	)		(12,878	)
Total earnings available for fixed charges:	$	183,226	$	90,124		$	179,785		$	437,911		$	275,937		$	144,470		$	287,740
Fixed charges:
Interest expense (1)	$	6,720	$	11,115		$	19,030		$	58,033		$	115,985		$	42,597		$	98,144
Portion of rent expense representative of interest (2)		7,974		9,525			12,552			17,202			28,199			12,552			18,683
Capitalized interest		—		127			2,919			3,564			17,503			4,045			12,878
Net preferred stock dividends (3)		12,699		37,827			36,223			36,166			40,387			19,891			12,407
Total fixed charges:	$	27,393	$	58,594		$	70,724		$	114,965		$	202,074		$	79,085		$	142,112
Ratio of earnings to fixed charges:		6.69x		1.54x			2.54x			3.81x			1.37x			1.83x			2.02x

(1)	Interest expense includes amortization of deferred debt issuance costs and discounts related to indebtedness.
(2)	The portion of operating rental expense that management believes is representative of interest is estimated to be 33%.
(3)	Net preferred stock dividends are the company’s preferred dividend expense net of income tax benefit.