Exhibit 12.1

Ratio of Earnings to Fixed Charges

(in millions)

	Nine Months Ended September 30,			Year Ended December 31,
	2014			2013		2012		2011		2010		2009
Earnings available for fixed charges:
Income before income taxes	$	(540	)	$	506	$	544	$	934	$	1,497	$	1,161
Fixed charges, excluding capitalized interest		190			197		133		108		66		55
Total earnings available for fixed charges	$	(350	)	$	703	$	677	$	1,042	$	1,563	$	1,216
Fixed charges:
Interest and debt expense (1)	$	140		$	143	$	93	$	65	$	39	$	34
Assumed interest element included in rent expense		54			57		41		43		27		21
Total Fixed charges	$	194		$	200	$	134	$	108	$	66	$	55
Ratio of earnings to fixed charges (2)		—			3.52		5.07		9.61		23.68		22.29

(1) Includes amortization of debt-related expenses plus capitalized interest.

(2) For the nine months ended September 30, 2014, earnings were insufficient to cover fixed charges by $350 million.