Exhibit 12.1 — Statement Re: Computation of Ratio of Earnings to Fixed Charges

	Three months ended
	March 31,		Year ended December 31,
	2008		2007			2006			2005		2004		2003
			(dollars in thousands except ratio data)
EARNINGS:
Consolidated pretax income from continued operations	$	9,216	$	265,737		$	315,701		$	175,985	$	68,310	$	37,431
Adjust: Income or loss from equity method investments		275		(974	)		(548	)		—		—		—
Add: Fixed charges		23,652		79,519			57,466			38,312		22,965		22,002
Total earnings	$	33,143	$	344,282		$	372,619		$	214,297	$	91,275	$	59,433
FIXED CHARGES:
Interest expense (1)	$	23,146	$	77,737		$	55,849		$	37,619	$	22,437	$	21,507
Interest portion of rental expense		506		1,782			1,617			693		528		495
Total fixed charges	$	23,652	$	79,519		$	57,466		$	38,312	$	22,965	$	22,002
Ratio of earnings to fixed charges		1.4		4.3			6.5			5.6		4.0		2.7
(1) Includes amortization of debt issuance costs.