12. Stock‑Based Compensation

For the years ended April 30, 2018, 2017 and 2016, the Company recorded stock‑based compensation expense of approximately $4,956,000, $3,392,000 and $4,002,000, respectively.

On January 14, 2007, the stockholders of the Company approved the 2006 Equity Incentive Plan, or 2006 Plan, effective January 21, 2007, for officers, directors, key employees and consultants. On September 29, 2011, the stockholders of the Company approved an amendment and restatement of the 2006 Plan, or Restated 2006 Plan. Under the Restated 2006 Plan, incentive stock options, nonqualified stock options, restricted stock awards, stock appreciation right awards, performance share awards, performance stock unit awards, dividend equivalents awards, stock payment awards, deferred stock awards, restricted stock unit awards, other stock‑based awards, performance bonus awards or performance‑based awards may be granted at the discretion of the compensation committee, which consists of outside directors. A maximum of 4,884,157 shares of stock may be issued pursuant to awards under the Restated 2006 Plan. The maximum number of shares of common stock with respect to one or more awards that may be granted to any one participant during any twelve month period is 2,000,000. A maximum of $5,000,000 may be paid in cash to any one participant as a performance‑based award during any twelve month period. The exercise price for any incentive stock option shall not be less than 100% of the fair market value on the date of grant. Vesting of awards is established at the time of grant.

The Company had an equity incentive plan, or 2002 Plan, for officers, directors and key employees. Under the 2002 Plan, incentive stock options or nonqualified stock options were granted, as determined by the administrator at the time of grant. Stock purchase rights were also granted under the 2002 Plan. Options under the 2002 Plan were granted at their fair market value (as determined by the board of directors). The options became exercisable at various times over a five-year period from the grant date. The 2002 Plan was terminated on the effective date of the 2006 Plan. Awards outstanding under the 2002 Plan remain outstanding and exercisable; no additional awards may be made under the 2002 Plan.

The Company had a 1992 nonqualified stock option plan, or 1992 Plan, for certain officers and key employees. Options under the 1992 Plan were granted at their fair market value (as determined by the board of directors) at the date of grant and became exercisable at various times over a five-year period from the grant date. The 1992 Plan expired in August 2002.

The fair value of stock options granted was estimated at the grant date using the Black‑Scholes option pricing model with the following weighted average assumptions for the years ended April 30, 2018, 2017 and 2016:


	Year Ended April 30,
	2018			2017			2016
Expected term (in years)		—			—			6.00
Expected volatility		—	%		—	%		36.14	%
Risk-free interest rate		—	%		—	%		1.88	%
Expected dividend		—			—			—
Weighted average fair value at grant date	$	—		$	—		$	10.18

No options were granted during the fiscal years ended April 30, 2018 and 2017.

The expected term of stock options represents the weighted average period the Company expects the stock options to remain outstanding, based on the Company’s historical exercise and post‑vesting cancellation experience and the remaining contractual life of its outstanding options.

The expected volatility is based on historical volatility for the Company’s stock.

The risk free interest rate is based on the implied yield on a U.S. Treasury zero‑coupon bond with a remaining term that approximates the expected term of the option.

The expected dividend yield of zero reflects that the Company has not paid any cash dividends since inception and does not anticipate paying cash dividends in the foreseeable future.

Information related to the stock option plans at April 30, 2018, 2017 and 2016, and for the years then ended is as follows:


	Restated 2006 Plan			2002 Plan			1992 Plan
		Weighted			Weighted			Weighted
		Average			Average			Average
		Exercise			Exercise			Exercise
	Shares	Price		Shares	Price		Shares	Price
Outstanding at April 30, 2015	652,117		23.96	44,993		7.57	78,604		0.59
Options granted	128,000		26.83	—		—	—		—
Options exercised	(43,000)		21.81	(31,161)		5.70	(10,000)		0.59
Options canceled	(58,318)		25.98	(8)		2.13	—		—
Outstanding at April 30, 2016	678,799		24.46	13,824		11.79	68,604		0.59
Options granted	—		—	—		—	—		—
Options exercised	(167,310)		22.32	(9,601)		11.79	(25,189)		0.59
Options canceled	(64,865)		26.76	(4,223)		11.79	—		—
Outstanding at April 30, 2017	446,624		24.93	—		—	43,415		0.59
Options granted	—		—	—		—	—		—
Options exercised	(107,598)		23.80	—		—	(25,113)		0.59
Options canceled	—		—	—		—	—		—
Outstanding at April 30, 2018	339,026		25.29	—		—	18,302		0.59
Options exercisable at April 30, 2018	256,012	$	24.81	—	$	—	18,302	$	0.59

The total intrinsic value of all options exercised during the years ended April 30, 2018, 2017 and 2016 was approximately $2,407,000, $1,747,000, and $1,198,000, respectively. The intrinsic value of all options outstanding at April 30, 2018 and 2017 was $10,890,000 and $2,840,000, respectively. The intrinsic value of all exercisable options at April 30, 2018 and 2017 was $8,587,000 and $2,454,000, respectively.

A summary of the status of the Company’s non‑vested stock options as of April 30, 2018 and the year then ended is as follows:


		Weighted
		Average
		Grant Date
Non-vested Options	Options	Fair Value
Non-vested at April 30, 2017	140,118	$	10.76
Granted	—		—
Expired	—		—
Canceled	—		—
Vested	(57,104)		10.45
Non-vested at April 30, 2018	83,014	$	10.97

As of April 30, 2018, there was approximately $7,045,000 of total unrecognized compensation cost related to non‑vested share‑based compensation awards granted under the equity plans. That cost is expected to be recognized over an approximately two‑year period or a weighted average period of approximately 1.9 years.

The weighted average fair value of options issued for the year ended April 30, 2016 was $10.18. No options were granted during the fiscal years ended April 30, 2018 and 2017. The total fair value of shares vesting during the years ended April 30, 2018, 2017 and 2016 was $3,328,000, $2,942,000 and $2,495,000, respectively.

Proceeds from all option exercises under all stock option plans for the years ended April 30, 2018, 2017 and 2016 were approximately $2,576,000, $3,863,000 and $1,121,000, respectively. The tax benefit realized from stock‑based compensation during the years ended April 30, 2018, 2017 and 2016 was approximately $0, $0, and $98,000, respectively.

The following tabulation summarizes certain information concerning outstanding and exercisable options at April 30, 2018:


				Options Outstanding
					Weighted
					Average			Options Exercisable
					Remaining	Weighted			Weighted
				As of	Contractual	Average		As of	Average
				April 30,	Life In	Exercise		April 30,	Exercise
Range of Exercise Prices				2018	Years	Price		2018	Price
$	0.59	-	19.16	72,302	4.23	$	13.78	72,302	$	13.78
	19.17	-	26.24	58,500	4.86		20.54	48,500		20.71
	26.25	-	26.99	80,000	7.15		26.70	32,000		26.70
	27.00	-	27.99	50,000	5.56		27.27	40,000		27.27
	28.00	-	32.19	96,526	4.59		29.90	81,512		29.65
$	0.59	-	32.19	357,328	5.27	$	24.02	274,314	$	23.20

The remaining weighted average contractual life of exercisable options at April 30, 2018 was 4.88 years.

Information related to the Company’s restricted stock awards at April 30, 2018 and for the year then ended is as follows:


	Restated 2006 Plan
		Weighted
		Average
		Grant Date
	Shares	Fair Value
Unvested stock at April 30, 2017	339,145	$	26.27
Stock granted	131,332		37.71
Stock vested	(133,886)		25.25
Stock canceled	(4,016)		26.10
Unvested stock at April 30, 2018	332,575	$	31.20