Exhibit 12.1

Computation of Ratio of Earnings to Fixed Charges

(dollars in thousands)

	Year Ended										Nine Months Ended
	December 31 2012		December 31 2013		December 31 2014		December 31 2015		December 31 2016		September 30 2016		September 30 2017
Earnings
Pre-tax income		44,448		65,147		92,684		75,676		59,030		42,169		31,775
Fixed charges		36,416		52,022		52,991		54,803		54,517		40,907		42,410
Capitalized interest amortization		89		94		94		94		94		71		5
Less:
Interest capitalized		257		—		—		—		—		—		—
Total earnings		80,696		117,263		145,769		130,573		113,641		83,147		74,190
Fixed Charges
Interest expense		35,541		51,404		52,353		54,030		53,604		40,229		41,665
Interest capitalized		257		—		—		—		—		—		—
Portion of rent estimated to represent the interest factor		618		618		638		773		913		678		745
Total fixed charges		36,416		52,022		52,991		54,803		54,517		40,907		42,410
Ratio		2.2		2.3		2.8		2.4		2.1		2.0		1.7