Exhibit 12.1

Ratio of Earnings to Fixed Charges

We have computed the ratio of earnings to fixed charges for each of the following periods on a consolidated basis. For purposes of computing the ratio of earnings to fixed charges, “earnings” consist of pretax income (loss) plus fixed charges (excluding capitalized interest). “Fixed charges” represent interest incurred (whether expensed or capitalized), amortization of debt expense and that portion of rental expense on operating leases deemed to be the equivalent of interest. You should read the ratio of earnings to fixed charges in conjunction with our combined consolidated financial statements and the related notes thereto which are incorporated by reference in this prospectus.

In millions	Historical
	Years Ended December 31,														Three Months Ended March 31,
	2011		2012			2013			2014			2015			2016
EARNINGS:
Earnings before income taxes less equity in earnings	$	11	$	48		$	24		$	78		$	269		$	88
Distributions received from unconsolidated affiliates, net of equity in earnings		—		—			—			—			3			7
Interest expense, net of capitalized interest		1		8			38			107			149			42
Capitalized interest		—		(1	)		(2	)		(6	)		(9	)		(1	)
Amortization of debt premium		—		—			—			(1	)		(1	)		—
Amortization of debt issuance costs		1		2			4			9			11			3
Estimated interest portion of rents (a)		—		—			1			3			4			2
Total Earnings (Losses)		13		57			65			190			426			141
FIXED CHARGES:
Interest expense whether expensed or capitalized		1		8			38			107			149			42
Amortization of debt premium		—		—			—			(1	)		(1	)		—
Amortization of debt issuance costs		1		2			4			9			11			3
Estimated interest portion of rents (a)		—		1			1			3			4			2
Total Fixed Charges	$	2	$	10		$	43		$	118		$	163		$	47
RATIO OF EARNINGS TO FIXED CHARGES		6.5		5.7			1.5			1.6			2.6			3.0
Deficiency amount		N/A		N/A			N/A			N/A			N/A			N/A

(a) Total rental expense was approximately $3 million, $4 million, $8 million, $15 million and $19 million for the years ended December 31, 2011, 2012, 2013, 2014 and 2015, respectively, and $8 million for the three months ended March 31, 2016.