Selected Quarterly Financial Data (unaudited)

Selected quarterly financial data for years ended December 31, 2018 and 2017 follows (in thousands, except per share data):



	Quarter Ended
	March 31,		June 30,		September 30,		December 31,
	2018		2018		2018		2018 ⁽¹⁾
Net sales	$	101,215	$	99,226	$	104,836	$	114,791
Gross margin	64,461		63,143		65,633		65,346
Net income	12,926		8,485		5,711		2,083
Earnings per share⁽²⁾:
Basic	$	0.24	$	0.15	$	0.10	$	0.04
Diluted	$	0.24	$	0.15	$	0.10	$	0.03

	Quarter Ended
	March 31,		June 30,		September 30,		December 31,
	2017		2017		2017		2017
Net sales ⁽³⁾	$	79,242	$	79,643	$	90,262	$	94,651
Gross margin	48,670		45,637		49,765		63,016
Net income (loss) ⁽³⁾	4,580		2,276		422		(2,071		)
Earnings (loss) per share^{(2) (3)}:
Basic	$	0.09	$	0.04	$	0.01	$	(0.04	)
Diluted	$	0.09	$	0.04	$	0.01	$	(0.04	)

⁽¹⁾Results of operations for the three months ended December 31, 2018 included out of period adjustments related to prior quarterly periods in 2018 and 2017. The aggregate out of period adjustment was approximately $1.8 million, reflecting a $0.9 million decrease to net sales, a $1.3 million increase to sales, general and administrative expense, and a $0.4 million decrease to provision for income taxes. Based on our quantitative and qualitative analysis, we do not consider the out of period impact to be material to our financial position or results of operations for any prior periods or for the quarter or year ended December 31, 2018.

⁽²⁾ Basic and diluted earnings per share are computed independently for each of the quarters presented. Therefore, the sum of quarterly basic and diluted per share information may not equal annual basic and diluted earnings per share.

⁽³⁾Amounts for 2017 have not been adjusted under the modified retrospective method of adoption of Topic 606, and are presented consistent with the prior period amounts reported under ASC 605.