EXHIBIT 12

STATEMENT REGARDING COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES AND RATIO OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS (UNAUDITED)

Year Ended December 31,

Three Months Ended March 31,

(dollars in thousands)

2010

2011

2012

2013

2014

2014

2015

Earnings:

Pretax income from continuing operations before adjustment for income or loss from equity investees⁽¹⁾

$

32,976

$

112,203

$

185,912

$

102,245

$

384,213

$

72,556

$

164,921

Fixed charges

134,905

290,240

359,947

460,918

485,762

122,108

123,348

Capitalized interest

(20,792)

(13,164)

(9,777)

(6,700)

(7,150)

(1,605)

(2,387)

Amortized premiums, discounts and capitalized expenses related to indebtedness

13,945

13,905

11,395

4,142

2,427

330

119

Noncontrolling interest in pre-tax income of subsidiaries that have not incurred fixed charges

(357)

4,894

2,415

6,770

(147)

1,175

(2,271)

Earnings

$

160,677

$

408,078

$

549,892

$

567,375

$

865,105

$

194,564

$

283,730

Fixed charges:

Interest expense⁽¹⁾

$

128,058

$

290,981

$

361,565

$

458,360

$

481,039

$

120,833

$

121,080

Capitalized interest

20,792

13,164

9,777

6,700

7,150

1,605

2,387

Amortized premiums, discounts and capitalized expenses related to indebtedness

(13,945)

(13,905)

(11,395)

(4,142)

(2,427)

(330)

(119)

Fixed charges

$

134,905

$

290,240

$

359,947

$

460,918

$

485,762

$

122,108

$

123,348

Consolidated ratio of earnings to fixed charges

1.19

1.41

1.53

1.23

1.78

1.59

2.30

Earnings:

Pretax income from continuing operations before adjustment for income or loss from equity investees⁽¹⁾

$

32,976

$

112,203

$

185,912

$

102,245

$

384,213

$

72,556

$

164,921

Fixed charges

134,905

290,240

359,947

460,918

485,762

122,108

123,348

Capitalized interest

(20,792)

(13,164)

(9,777)

(6,700)

(7,150)

(1,605)

(2,387)

Amortized premiums, discounts and capitalized expenses related to indebtedness

13,945

13,905

11,395

4,142

2,427

330

119

Noncontrolling interest in pre-tax income of subsidiaries that have not incurred fixed charges

(357)

4,894

2,415

6,770

(147)

1,175

(2,271)

Earnings

$

160,677

$

408,078

$

549,892

$

567,375

$

865,105

$

194,564

$

283,730

Fixed charges:

Interest expense⁽¹⁾

$

128,058

$

290,981

$

361,565

$

458,360

$

481,039

$

120,833

$

121,080

Capitalized interest

20,792

13,164

9,777

6,700

7,150

1,605

2,387

Amortized premiums, discounts and capitalized expenses related to indebtedness

(13,945)

(13,905)

(11,395)

(4,142)

(2,427)

(330)

(119)

Fixed charges

134,905

290,240

359,947

460,918

485,762

122,108

123,348

Preferred stock dividends

21,645

60,502

69,129

66,336

65,408

16,353

16,352

Combined fixed charges and preferred stock dividends

$

156,550

$

350,742

$

429,076

$

527,254

$

551,170

$

138,461

$

139,700

Consolidated ratio of earnings to combined fixed charges and preferred stock dividends

1.03

1.16

1.28

1.08

1.57

1.41

2.03

(1) We have reclassified the income and expenses attributable to the properties sold prior to or held for sale at January 1, 2014 to discontinued operations.