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				Six Months Ended
	November 30, 2015		November 30, 2014		November 30, 2015		November 30, 2014

Share-based compensation expense	$	7,005	$	5,079	$	13,472	$	9,145
Income tax benefit	$	2,279	$	1,720	$	4,637	$	2,824

Share-Based Awards

The following table summarizes the changes in unvested share-based awards for the six months ended November 30, 2015 (shares in thousands):



	Shares		Weighted-Average Grant-Date Fair Value

Unvested at May 31, 2015	1,848		$	29
Granted	450		57
Vested	(620	)	27
Forfeited	(37	)	32
Unvested at November 30, 2015	1,641		$	37

The total fair value of share-based awards vested during the six months ended November 30, 2015 and November 30, 2014 was $17.6 million and $14.6 million, respectively.

For these share-based awards, we recognized compensation expense of $6.4 million and $4.7 million during the three months ended November 30, 2015 and November 30, 2014, respectively. We recognized compensation expense of $12.6 million and $8.5 million during the six months ended November 30, 2015 and November 30, 2014, respectively. As of November 30, 2015, there was $52.0 million of unrecognized compensation expense related to unvested share-based awards that we expect to recognize over a weighted-average period of 2.30 years.

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 November 30, 2015, 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 November 30, 2015 and November 30, 2014, respectively. We recognized compensation expense for the plan of $0.3 million and $0.3 million in the six months ended November 30, 2015 and November 30, 2014, respectively.

The weighted-average grant-date fair value of each designated share purchased under this plan during the six months ended November 30, 2015 and November 30, 2014 was approximately $7 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 six months ended November 30, 2015 and November 30, 2014, 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 six months ended November 30, 2015:



	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	(128	)	23
Outstanding at November 30, 2015	905		$	31	5.7	$	37.3

Options vested and exercisable at November 30, 2015	586		$	23	4.0	$	28.6

We recognized compensation expense for stock options of $0.4 million and $0.2 million during the three months ended November 30, 2015 and November 30, 2014, respectively. We recognized compensation expense for stock options of $0.6 million and $0.3 million during the six months ended November 30, 2015 and November 30, 2014, respectively. The aggregate intrinsic value of stock options exercised during the six months ended November 30, 2015 and November 30, 2014 was $4.8 million and $10.4 million, respectively. As of November 30, 2015, 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 2.3 years.

The weighted-average grant-date fair value of each stock option granted during the six months ended November 30, 2015 and November 30, 2014 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:



	Six Months Ended
	November 30, 2015	November 30, 2014
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.