Exhibit 12.1

Ratio of Earnings to Fixed Charges

	Three Months Ended March 31,						Year Ended December 31,
	2012			2011			2011			2010			2009			2008			2007
Earnings:
(a) pre-tax income (loss) from continuing operations before adjustment for income or loss from equity investees		(831	)		(44,776	)		6,030			105,098			40,177			46,706			273,523
(b) fixed charges		36,697			44,156			152,074			170,047			145,103			353,355			185,719
(c) amortization of capitalized interest		220			217			874			623			832			21			—
(d) distributed income of equity investees		8,104			6,126			30,143			22,197			18,944			13,250			678
(e) share of pre-tax losses of equity investees for which charges arising from guarantees are included in fixed charges		—			—			—			—			—			—			—
Less:
(a) Interest capitalized		(1,048	)		(3,242	)		(4,303	)		(11,295	)		(11,854	)		(4,070	)		(54	)
(b) preference security dividend requirements of consolidated subsidiaries		—			(27	)		(27	)		—			—			—			—
Total		43,142			2,454			184,791			286,670			193,202			409,262			459,866

	Three Months Ended March 31,					Year Ended December 31,
	2012		2011			2011		2010		2009		2008		2007
Fixed charges:
(a) Interest expensed and capitalized		25,577		32,462			105,904		105,565		68,790		51,121		49,287
(b) amortization of debt expense and discount or premium and capitalized expenses related to indebtedness		1,332		1,331			5,580		11,752		6,682		2,077		1,856
(c) an estimate of the interest within rental expense		9,788		10,336			40,563		52,730		69,631		300,157		134,576
(d) preference security dividend requirements of consolidated subsidiaries		—		27			27		—		—		—		—
Total		36,697		44,156			152,074		170,047		145,103		353,355		185,719
Earnings to fixed charges		1.18		(A	)		1.22		1.69		1.33		1.16		2.48
(A) Additional pre-tax income from continuing operations before adjustment for income or loss from equity investees of $41,702 would be necessary to generate a ratio of earnings to fixed charges of 1.00