Exhibit 12.1

RATIO OF EARNINGS TO FIXED CHARGES

The following table sets forth our ratio of earnings to fixed charges for the periods indicated (dollars in thousands):

	Year ended December 31,
	2013			2012			2011			2010			2009
Fixed Charges:
Interest expense	$	39,152		$	26,060		$	32,724		$	27,107		$	17,113
Capitalized interest		2,694			2,663			2,175			9,885			22,825
Amortization of public offering costs		2,143			1,146			2,050			3,835			989
Portion of rent expense representative of interest		4,864			3,986			4,028			3,343			3,774
Total fixed charges	$	48,853		$	33,855		$	40,977		$	44,170		$	44,701
Earnings available for fixed charges:
Net income (loss) from continuing operations before income taxes	$	(808,679	)	$	119,484		$	208,245		$	(91,125	)	$	(74,672	)
Fixed charges above		48,852			33,855			40,977			44,170			44,701
Less interest capitalized		(2,694	)		(2,663	)		(2,175	)		(9,885	)		(22,825	)
Current period amortization of capitalized interest		6,899			5,725			6,429			3,294			1,436
Total earnings available for fixed charges		(755,622	)		156,401			253,476			(53,546	)		(51,360	)
Earnings sufficient (insufficient) to cover fixed charges	$	(804,475	)	$	122,546		$	212,499		$	(97,716	)	$	(96,061	)
Ratio of earnings to fixed charges		N/A			4.62x			6.19x			N/A			N/A

N/A - represents coverage ratio of less than 1.