Exhibit 12.1

	Year Ended December 31,
	2013			2014			2015			2016			2017
Earnings (loss)	$	4,429		$	(7,425	)	$	20,327		$	37,843		$	28,448
Fixed charges		2,667			1,262			834			1,996			8,382
Ratio of earnings to fixed charges		1.66	x		(5.88	)x		24.37	x		18.96	x		3.39	x
Coverage deficiency		—		$	8,687			—			—			—