EXHIBIT 12

Statement re: Calculation of Ratios of Earnings to

Combined Fixed Charges and Preferred Stock Dividends

(in thousands, except ratios)

	Year Ended December 31, 2010				Year Ended December 31, 2009				Year Ended December 31, 2008			Year Ended December 31, 2007		Year Ended December 31, 2006
Net income (loss) from continuing operations, less preferred dividends	$	(40,895	)		$	(330,576	)		$	13,506		$	101,302	$	99,536
Preferred dividends	69,468				73,451				71,426			58,292		56,419
Interest expense	237,848				204,573				181,637			157,811		154,850
Earnings (loss) before fixed charges	$	266,421			$	(52,552	)		$	266,569		$	317,405	$	310,805
Interest expense	$	237,848			$	204,573			$	181,637		$	157,811	$	154,850
Interest costs capitalized	11,498				26,864				53,456			59,167		36,260
Total fixed charges	249,346				231,437				235,093			216,978		191,110
Preferred dividends	69,468				73,451				71,426			58,292		56,419
Total fixed charges and preferred dividends	$	318,814			$	304,888			$	306,519		$	275,270	$	247,529
Ratio of earnings to fixed charges	1.07				N/A			(2)	1.13			1.46		1.63
Ratio of earnings to fixed charges and preferred dividends	N/A			(1)	N/A			(3)	N/A		(4)	1.15		1.26

(1) N/A – the ratio is less than 1.0; deficit of $52.4 million exists for the year ended December 31, 2010. The calculation of earnings includes $346.8 million of non-cash depreciation expense.

(2) N/A – the ratio is less than 1.0; deficit of $284.0 million exists for the year ended December 31, 2009. The calculation of earnings includes $321.0 million of non-cash depreciation expense.

(3) N/A – the ratio is less than 1.0; deficit of $357.4 million exists for the year ended December 31, 2009. The calculation of earnings includes $321.0 million of non-cash depreciation expense.

(4) N/A – the ratio is less than 1.0; deficit of $40.0 million exists for the year ended December 31, 2008. The calculation of earnings includes $289.7 million of non-cash depreciation expense.