Exhibit 12.1

RATIO OF EARNINGS TO FIXED CHARGES

The following table contains our consolidated ratio of earnings to fixed charges for the periods indicated. You should read these ratios in connection with our consolidated financial statements, including the notes to those financial statements (amounts in table in thousands, except ratios).

	For the six months ended June 30,			For the years ended December 31,
	2015			2014			2013			2012			2011			2010
Income (loss) before income taxes	$	(322,953	)	$	175,129		$	54,791		$	(34,691	)	$	(15,830	)	$	9,898
Add:
Fixed charges (see below)		10,984			9,060			8,162			2,835			2,206			55
Amortization of capitalized interest		480			607			383			187			7			—
Less:
Interest capitalized		(2,306	)		(2,831	)		(1,888	)		(1,574	)		(1,278	)		—
Non-controlling interest in pre-tax income of subs that have not incurred fixed charges		(111	)		17
Total earnings	$	(313,906	)	$	181,982		$	61,448		$	(33,243	)	$	(14,895	)	$	9,953
Fixed charges
Interest expensed	$	7,939		$	5,334		$	5,687		$	1,002		$	683		$	3
Interest capitalized		2,306			2,831			1,888			1,574			1,278			—
Amortized premiums, discounts & capitalized expenses related to indebtedness		704			850			547			231			221			33
Estimate of interest within rental expense		34			44			40			28			24			19
Total fixed charges	$	10,983		$	9,059		$	8,162		$	2,835		$	2,206		$	55
Ratio of earnings to fixed charges		(a)			20.09			7.53			(a)			(a)			179.99

(a) During the period noted, our coverage ratio was less than 1:1. We would have needed to generate additional earnings of approximately $324.9 million during the six months ended June 30, 2015, $36.1 million during the year ended December 31, 2012 and $17.1 million during the year ended December 31, 2011 to achieve a coverage ratio of 1:1.