SHARE-BASED AWARDS AND OPTIONS

The following table summarizes share-based compensation expense and the related income tax benefit recognized for our share-based awards and stock options (in thousands):



	Three Months Ended				Nine Months Ended
	February 29, 2016		February 28, 2015		February 29, 2016		February 28, 2015

Share-based compensation expense	$	7,000	$	5,682	$	20,472	$	14,827
Income tax benefit	$	2,191	$	1,945	$	6,828	$	4,769

Share-Based Awards

The following table summarizes the changes in unvested share-based awards for the nine months ended February 29, 2016 (shares in thousands):



	Shares		Weighted-Average Grant-Date Fair Value

Unvested at May 31, 2015	1,848		$	29
Granted	450		57
Vested	(623	)	27
Forfeited	(51	)	34
Unvested at February 29, 2016	1,624		$	37

The total fair value of share-based awards vested during the nine months ended February 29, 2016 and February 28, 2015 was $17.0 million and $14.9 million, respectively.

For these share-based awards, we recognized compensation expense of $6.5 million and $5.4 million during the three months ended February 29, 2016 and February 28, 2015, respectively. We recognized compensation expense of $19.0 million and $13.8 million during the nine months ended February 29, 2016 and February 28, 2015, respectively. As of February 29, 2016, there was $43.4 million of unrecognized compensation expense related to unvested share-based awards that we expect to recognize over a weighted-average period of 2.1 years. Our share-based award plans provide for accelerated vesting under certain conditions.

Employee Stock Purchase Plan

We have an employee stock purchase plan under which the sale of 4.8 million shares of our common stock has been authorized. Employees may designate up to the lesser of $25,000 or 20% of their annual compensation for the purchase of our common stock. The price for shares purchased under the plan is 85% of the market value on the last day of each calendar quarter. As of February 29, 2016, 2.3 million shares had been issued under this plan, with 2.5 million shares reserved for future issuance. We recognized compensation expense for the plan of $0.2 million and $0.1 million in the three months ended February 29, 2016 and February 28, 2015, respectively. We recognized compensation expense for the plan of $0.5 million and $0.5 million in the nine months ended February 29, 2016 and February 28, 2015, respectively.

The weighted-average grant-date fair value of each designated share purchased under this plan during the nine months ended February 29, 2016 and February 28, 2015 was approximately $8 and $4, respectively, which represents the fair value of the 15% discount.

Stock Options

Stock options are granted with an exercise price equal to 100% of fair market value on the date of grant and have a term of ten years. Stock options granted before fiscal 2015 vest in equal installments on each of the first four anniversaries of the grant date. Stock options granted during fiscal 2015 and thereafter vest in equal installments on each of the first three anniversaries of the grant date. During the nine months ended February 29, 2016 and February 28, 2015, we granted 0.1 million and 0.4 million stock options, respectively. Our stock option plans provide for accelerated vesting under certain conditions.

The following is a summary of our stock option activity as of and for the nine months ended February 29, 2016:



	Options		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
	(in thousands)				(in years)	(in millions)
Outstanding at May 31, 2015	894		$	26	5.2	$	23.9
Granted	145		56
Forfeited	(6	)	16
Exercised	(138	)	23
Outstanding at February 29, 2016	895		$	31	5.6	$	27.3

Options vested and exercisable at February 29, 2016	575		$	23	3.8	$	22.0

We recognized compensation expense for stock options of $0.4 million and $0.2 million during the three months ended February 29, 2016 and February 28, 2015, respectively. We recognized compensation expense for stock options of $1.0 million and $0.5 million during the nine months ended February 29, 2016 and February 28, 2015, respectively. The aggregate intrinsic value of stock options exercised during the nine months ended February 29, 2016 and February 28, 2015 was $5.2 million and $11.7 million, respectively. As of February 29, 2016, we had $3.3 million of unrecognized compensation expense related to unvested stock options that we expect to recognize over a weighted-average period of 2.1 years.

The weighted-average grant-date fair value of each stock option granted during the nine months ended February 29, 2016 and February 28, 2015 was $16 and $9, respectively. Fair value was estimated on the date of grant using the Black-Scholes valuation model with the following weighted-average assumptions:



	Nine Months Ended
	February 29, 2016	February 28, 2015
Risk-free interest rate	1.62%	1.57%
Expected volatility	28.65%	23.65%
Dividend yield	0.10%	0.13%
Expected life (years)	5	5

The risk-free interest rate is based on the yield of a zero coupon U.S. Treasury security with a maturity equal to the expected life of the option from the date of the grant. Our assumption on expected volatility is based on our historical volatility. The dividend yield assumption is calculated using our average stock price over the preceding year and the annualized amount of our most current quarterly dividend per share. We based our assumptions on the expected lives of the options on our analysis of the historical exercise patterns of the options and our assumption on the future exercise pattern of options.