Note 18 — Quarterly financial data (unaudited)

	First		Second		Third		Fourth
2016:
Sales	$	372,220	$	437,592	$	489,899	$	509,283
Gross margin		196,907		248,405		273,220		274,967
Net income		41,161		70,601		84,214		75,867
Earnings per share:
Basic		0.72		1.24		1.48		1.33
Diluted		0.72		1.23		1.46		1.31
2015:
Sales	$	379,008	$	400,727	$	462,731	$	446,200
Gross margin		208,721		221,890		248,492		234,861
Net income		42,885		49,214		69,388		49,624
Earnings per share:
Basic		0.69		0.81		1.15		0.84
Diluted		0.69		0.80		1.14		0.84

The sum of the per-share amounts for the four quarters may not always equal the annual per-share amounts due to differences in the average number of shares outstanding during the respective periods.

During the fourth quarter of 2016, we recorded pre-tax severance and restructuring costs of $6,411.

During the third quarter of 2016, we recorded pre-tax severance and restructuring costs of $1,714 and we recorded other expense of $2,722 related to the reversal of an indemnification asset resulting from the effective settlement of a tax exam. Additionally, our income tax provision for the third quarter included a discrete tax benefit of $1,651 related to the effective settlement of a tax exam.

During the second quarter of 2016, we recorded pre-tax severance and restructuring costs of $1,633. Additionally, we recorded other income of $800 related to a favorable litigation settlement and a $1,192 favorable adjustment to unrecognized tax benefits related to the effective settlement of a tax exam. Furthermore, our income tax provision for the second quarter included a discrete tax benedit of $1,136 related to the effective settlement of a tax exam.

During the first quarter of 2016, we recorded pre-tax severance and restructuring costs of $1,017.

On December 18, 2015, the Protecting Americans from Tax Hikes Act of 2015 was enacted which retroactively reinstated the Federal Research and Development Tax Credit (Federal R&D Tax Credit) as of January 1, 2015, and made it permanent. As a result, our income tax provision for the three months ended January 31, 2016 includes a discrete tax benefit of $2,025 primarily related to 2015. Additionally, our income tax provision for the first quarter included a discrete tax benefit of $6,184 related to dividends paid from previously taxed foreign earnings.

During the fourth quarter of 2015, we recorded pre-tax severance and restructuring costs of $9,092. Additionally, we recorded other income of $1,608 related to a favorable litigation settlement.

During the third quarter of 2015, we recorded pre-tax severance and restructuring costs of $2,319.

During the first quarter of 2015, we recorded a pre-tax loss of $1,572 related to a pension settlement.

On December 19, 2014, the Tax Increase Prevention Act of 2014 was enacted which retroactively reinstated the Federal R&D Tax Credit from January 1, 2014 to December 31, 2014 and extended certain other tax provisions. As a result, our income tax provision for the first quarter of 2015 included a discrete tax benefit of $1,786 primarily related to 2014.