	2018		2017		2016
Stock options	$	2,482	$	2,344	$	2,281
Stock awards		8,930		13,419		9,680
Total stock-based compensation expense⁽¹⁾		11,412		15,763		11,961
Income tax benefit		2,750		5,249		3,947
Total stock-based compensation expense, net of tax	$	8,662	$	10,514	$	8,014

⁽¹⁾	Decrease in 2018 stock-based compensation expense reflects the cumulative impact of the change in the expected achievements of certain performance targets.

A summary of our stock option activity was as follows (in thousands, except per share amounts and years):

	Stock Options			Weighted- Average Exercise Price per Share		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value ⁽¹⁾
Balance at December 30, 2017		1,355		$	20.23		6.2	$	23,515
Granted		170			33.72
Exercised		(186	)		14.96
Canceled/Forfeited		(17	)		26.43
Outstanding at December 29, 2018		1,322		$	22.64		5.9	$	13,009
Exercisable at December 29, 2018		898		$	20.76		4.8	$	10,332
Vested and expected to vest at December 29, 2018		1,295		$	22.55		5.9	$	12,841

Other information pertaining to options was as follows (in thousands, except per share amounts):

	2018		2017		2016
Weighted-average grant date fair value of stock options granted	$	13.96	$	10.33	$	8.85
Total intrinsic value (at exercise) of stock options exercised	$	3,459	$	3,586	$	2,088

Cash received from the exercise of stock options for the fiscal year ended December 29, 2018 was $2.8 million. Our tax benefit related to the exercise of stock options for the fiscal year ended December 29, 2018 was $0.8 million.

At December 29, 2018, there was $2.7 million of total stock option compensation expense related to non-vested stock options not yet recognized, which is expected to be recognized over a weighted-average period of 1.7 years.

During 2016, 30,500 market-based stock options were granted and had a weighted-average grant date fair value of $10.25 per option. These options are reflected in the stock option activity table above. There were no market-based stock options granted in 2018 or 2017. The assumptions used to calculate the fair value of market-based stock options granted using the Monte Carlo simulation model were as follows:

Valuation Assumptions	2018	2017	2016
Expected dividend yield	NA	NA		0	%
Expected volatility	NA	NA		50	%
Risk-free interest rate	NA	NA		1.8	%

Except for the market-based stock options discussed above, the fair value of options granted was calculated using the Black-Scholes-Merton option-pricing model.

The assumptions used to calculate the fair value of options granted using the Black-Scholes-Merton option-pricing model were as follows:

Valuation Assumptions	2018			2017			2016
Expected dividend yield		0	%		0	%		0	%
Expected volatility		43	%		46	%		50	%
Risk-free interest rate		2.7	%		2.0	%		1.4	%
Expected term (in years)		5.0			5.1			5.2

	Time- Based Stock Awards			Weighted-Average Grant Date Fair Value		Performance- and Market-Based Stock Awards			Weighted-Average Grant Date Fair Value
Outstanding at December 30, 2017		395		$	23.77		1,063		$	23.41
Granted		222			33.53		200			34.46
Vested		(172	)		24.28		(151	)		33.34
Canceled/Forfeited		(62	)		26.76		(51	)		27.44
Outstanding at December 29, 2018		383		$	28.66		1,061		$	23.91

At December 29, 2018, there was $4.2 million of unrecognized compensation expense related to non-vested time-based stock awards, which is expected to be recognized over a weighted-average period of 1.8 years and $12.4 million of unrecognized compensation expense related to non-vested performance-based and market-based stock awards, which is expected to be recognized over a weighted-average period of 1.9 years.

During 2018, 5,027 performance-based stock awards with a market condition were granted and had a weighted-average grant date fair value of $35.97 per award. These stock awards are reflected in the "Performance- and Market-Based Stock Awards" column in the stock award activity table above. During 2017, 270,895 performance-based stock awards with a market condition were granted and had a weighted-average grant date fair value of $22.40 per award. There were no market-based stock awards granted in 2016.

The assumptions used to calculate the fair value of the 2018 and 2017 performance-based stock awards with a market condition, using the Monte Carlo simulation model, were as follows:

Valuation Assumptions	2018			2017			2016
Expected dividend yield		0	%		0	%	NA
Expected volatility		43	%		46	%	NA
Risk-free interest rate		2.6	%		1.5	%	NA

	2018		2017		2016
Amount repurchased under Board-approved share repurchase program	$	279,101	$	150,000	$	125,000
Amount repurchased in connection with the vesting of employee restricted stock grants		3,344		5,245		1,693
Total amount repurchased	$	282,445	$	155,245	$	126,693

As of December 29, 2018, the remaining authorization under our Board-approved share repurchase program was $186 million. There is no expiration date governing the period over which we can repurchase shares. Any repurchased shares are constructively retired and returned to an unissued status. The cost of stock repurchases is first charged to additional paid-in-capital. Once additional paid-in capital is reduced to zero, any additional amounts are charged to retained earnings.

The components of basic and diluted net income per share were as follows (in thousands, except per share amounts):

	2018		2017		2016
Net income	$	69,539	$	65,077	$	51,417
Reconciliation of weighted-average shares outstanding:
Basic weighted-average shares outstanding		35,256		41,212		46,154
Dilutive effect of stock-based awards		909		873		748
Diluted weighted-average shares outstanding		36,165		42,085		46,902
Net income per share – basic	$	1.97	$	1.58	$	1.11
Net income per share – diluted	$	1.92	$	1.55	$	1.10

Additional potential dilutive stock options totaling 0.2 million, 0.4 million and 0.6 million for 2018, 2017 and 2016, respectively, have been excluded from our diluted net income per share calculations because these securities’ exercise prices were anti-dilutive (e.g., greater than the average market price of our common stock).