9. Share‑Based Compensation

CRA recorded approximately $3.5 million, $4.8 million, and $6.6 million of compensation expense for fiscal 2019, fiscal 2018, and fiscal 2017, respectively, for share‑based awards consisting of stock options, shares of restricted stock, time‑vesting restricted stock units, and performance-vesting restricted stock units issued to employees, directors, and non-employees based on their respective estimated grant date fair values. Performance-vesting restricted stock units are expensed using the graded acceleration method.

Share-based Compensation Plans. As of December 28, 2019, CRA’s active equity-based compensation plans consist of its Amended and Restated 2006 Equity Incentive Plan, as amended (the “2006 Equity Plan”), and its 1998 Employee Stock Purchase Plan (the “1998 ESPP”), a tax-qualified plan under Section 423 of the Internal Revenue Code. During fiscal 2009, CRA implemented a long-term incentive program, or “LTIP,” as a framework for grants made under the 2006 Equity Plan to its senior corporate leaders, practice leaders and key revenue generators. Under the LTIP, participants have received a mixture of stock options, time-vesting restricted stock units, and performance-vesting restricted stock units. In December 2016, CRA’s Board of Directors amended CRA’s Cash Incentive Plan to facilitate the grant to LTIP participants of service-based and performance-based cash awards as a component of the LTIP. The LTIP is designed to reward CRA’s senior corporate leaders, practice leaders and key revenue generators and provide them with the opportunity to share in the long-term growth of CRA.

2006 Equity Plan: Maximum and Available Shares. The 2006 Equity Plan authorizes the grant of a variety of incentive and performance awards to CRA’s directors, employees and non-employee experts, including stock options, shares of restricted stock, restricted stock units, and other equity awards. The shares available for grant under the 2006 Equity Plan as of December 28, 2019 was 623,212.

Stock Options. A summary of option activity during fiscal 2019 from the 2006 Equity Plan is as follows.


		Weighted		Weighted Average
		Average		Remaining	Aggregate
		Exercise		Contractual	Intrinsic
	Options	Price		Term	Value
					(in thousands)
Outstanding at December 29, 2018	585,981	$	25.48		$	9,286
Fiscal 2019:
Granted	—		—
Exercised	(140,513)		22.85		$	3,659
Expired	—		—
Forfeited	(979)		21.52		$	28
Outstanding at December 28, 2019	444,489	$	26.31	2.81	$	12,115
Options exercisable at December 28, 2019	408,277	$	24.84	2.39	$	11,732
Vested or expected to vest at December 28, 2019	444,281	$	26.31	2.80	$	12,113

The weighted average fair market value using the Black‑Scholes option‑pricing model of the stock options granted under the 2006 Equity Incentive Plan in fiscal 2018 and fiscal 2017 was $19.96 and $11.54, respectively. There were no stock options granted in fiscal 2019. The fair market value of the stock options at the date of grant were estimated using the Black‑Scholes option‑pricing model with the following weighted average assumptions:


	Fiscal		Fiscal
	Year		Year
	2018		2017
Risk-free interest rate	2.8	%	2.1	%
Expected volatility	39	%	32	%
Expected dividend yield	1.7	%	1.5	%
Forfeiture rate	0.4	%	0.4	%
Weighted average expected life (in years)	10.00		4.49

The risk-free interest rate is based on U.S. Treasury interest rates with corresponding terms consistent with the expected life of the stock options. Expected volatility and expected life are based on CRA’s historical experience. Expected dividend yield was determined based on CRA’s annualized dividend rate per share, as a percentage of average market price of the common stock, on each dividend payment date. The forfeiture rate used was based upon historical experience. CRA believes its historical experience is an appropriate indicator of future forfeitures.

The aggregate intrinsic value of stock options exercised in fiscal 2019, fiscal 2018, and fiscal 2017 was approximately $3.7 million, $3.0 million, and $5.4 million, respectively.

The following table provides a roll-forward of the outstanding non-vested stock options over fiscal 2019:


	Options
		Weighted-Average
	Number of	Grant Date
	Shares	Fair Value
Non-vested at December 29, 2018	116,284	$	10.64
Granted	—		—
Vested	(79,093)		8.77
Forfeited	(979)		7.37
Non-vested at December 28, 2019	36,212	$	14.80

The total fair value of stock options that vested during fiscal 2019, fiscal 2018, and fiscal 2017 was $0.7 million, $1.1 million, and $1.5 million, respectively. As of December 28, 2019, there was $0.5 million of total unrecognized compensation cost, net of expected forfeitures, related to non‑vested stock options granted. That cost is expected to be recognized over a weighted‑average period of 2.5 years. Options granted during or prior to fiscal 2016 expire on the seventh anniversary of the date of grant. Options granted during fiscal 2017 and fiscal 2018 expire on the tenth anniversary of the date of grant.

Restricted Stock. CRA grants shares of restricted stock, which are subject to the execution of a restricted stock agreement, under its 2006 Equity Incentive Plan. Generally, shares of restricted stock vest in four equal annual installments beginning on the first anniversary of the date of grant. Total unrecognized compensation cost, net of expected forfeitures, related to shares of restricted stock as of December 28, 2019 was $0.9 million, which is expected to be recognized over a weighted-average period of 2.6 years. The forfeiture rate of 0.9% used for shares of restricted stock was based upon historical experience. CRA believes its historical experience is an appropriate indicator of future forfeitures.

The following table provides a roll-forward of the shares of restricted stock under the 2006 Equity Incentive Plan over fiscal 2019:


	Shares of Restricted Stock
		Weighted-Average
	Number of	Grant Date
	Shares	Fair Value
Non-vested at December 29, 2018	36,006	$	35.41
Granted	11,772		38.21
Vested	(16,255)		31.14
Forfeited	—		—
Non-vested at December 28, 2019	31,523	$	38.66

The total fair value of shares of restricted stock that vested during fiscal 2019, fiscal 2018, and fiscal 2017 was $0.5 million, $0.6 million, and $0.6 million, respectively.

Time-Vesting RSUs. CRA grants time-vesting restricted stock units, which are subject to the execution of a restricted stock unit agreement, under its 2006 Equity Incentive Plan. Generally, time-vesting restricted stock units vest in four equal annual installments beginning on the first anniversary of the date of grant. Total unrecognized compensation cost, net of expected forfeitures, related to time-vesting restricted stock units as of December 28, 2019 was $2.4 million, which is expected to be recognized over a weighted-average period of 3.1 years. The forfeiture rate of 0.9% used for time-vesting restricted stock units was based upon historical experience. CRA believes its historical experience is an appropriate indicator of future forfeitures.

The following table provides a roll-forward of the time-vesting restricted stock units under the 2006 Equity Incentive Plan over fiscal 2019:


	Time-Vesting
	Restricted Stock Units
		Weighted-Average
	Number of	Grant Date
	Units	Fair Value
Non-vested at December 29, 2018	79,759	$	33.64
Granted	31,226		46.20
Vested	(45,858)		27.91
Forfeited	(489)		21.52
Non-vested at December 28, 2019	64,638	$	43.87

The total fair value of time-vesting restricted stock units that vested during fiscal 2019, fiscal 2018, and fiscal 2017 was $1.3 million, $1.7 million, and $2.0 million, respectively.

Performance-Vesting RSUs. CRA grants performance-vesting restricted stock units (“PRSUs”), which are subject to the execution of a restricted stock unit agreement, under its 2006 Equity Incentive Plan. Generally, achievement of performance measures for PRSUs are based on a two-year performance period, after which the units determined based on this achievement will vest three-fourths in the first year following the performance period and one-fourth on the fourth anniversary of the date of grant. The number of units determined based on the achievement of a PRSUs performance measures generally ranges from 50% to 125% of the PRSU’s target number of units.

In accordance with ASC Topic 718, for PRSUs awarded to employees, CRA estimates share-based compensation cost at the grant date based on the fair value of the award and recognizes the cost over the requisite service period using the graded acceleration method.

The following table provides a roll-forward of the performance-vesting restricted stock units under the 2006 Equity Incentive Plan over fiscal 2019. For purposes of this table, granted PRSUs are counted based on the maximum number of units that could vest upon achievement of the PRSUs’ performance conditions which, for all periods presented, equaled 125% of the PRSU’s target number of units.


	Performance-Vesting
	Restricted Stock Units
		Weighted-Average
		Grant Date
	Number of Units	Fair Value
Non-vested at December 29, 2018	121,950	$	32.92
Granted	29,234		51.31
Vested	(65,976)		25.27
Forfeited	(3,058)		28.77
Non-vested at December 28, 2019	82,150	$	45.88

1998 ESPP. In fiscal 1998, CRA adopted the 1998 ESPP, a tax-qualified plan under Section 423 of the Internal Revenue Code. The 1998 ESPP authorizes the issuance of up to an aggregate of 243,000 shares of common stock to participating employees at a purchase price equal to 85% of fair market value on either the first or the last day of the one-year offering period under the plan. In fiscal 2019, fiscal 2018, and fiscal 2017, there were no offering periods under this plan and no shares were issued. As of December 28, 2019, 211,777 shares are available for grant under the 1998 ESPP.