Exhibit 12.1

RATIO OF EARNINGS TO FIXED CHARGES (unaudited)

	Year Ended December 31,															Six Months Ended June 30, 2011			Six Months Ended June 30, 2010
	2010			2009			2008(1)			2007			2006
	(dollars in thousands)
Earnings:
Income (loss) before income taxes	$	20,760		$	(6,169	)	$	(210,870	)	$	116,498		$	98,390		$	(15,224	)	$	(21,823	)
Fixed charges (excluding capitalized interest)		121,971			107,537			77,307			58,430			50,954			52,609			68,863
Amortization of capitalized interest		4,966			3,476			2,110			1,040			405			6,480			6,483
Total earnings	$	147,697		$	104,844		$	(131,453	)	$	175,968		$	149,749		$	43,865		$	53,523
Fixed charges:
Interest expense (including amortization of debt discount and issuance costs), net of capitalized interest	$	121,233		$	106,849		$	76,639		$	57,742		$	50,291		$	52,219		$	68,499
Capitalized interest		684			8,964			14,091			19,879			8,120			152			430
Estimated interest component of rent expense		738			688			668			688			663			390			364
Total fixed charges	$	122,655		$	116,501		$	91,398		$	78,309		$	59,074		$	52,761		$	69,293
Ratio of earnings to fixed charges		1.20	x		0.90	x		—			2.25	x		2.53	x		0.83	x		0.77	x

(1) For the year ended December 31, 2008, earnings were insufficient to cover fixed charges by $40,055.