The company maintains the 2010 plan for executive officers, other employees, and non-employee members of the company's Board of Directors. The 2010 plan allows the company to grant equity-based compensation awards, including stock options, restricted stock units, restricted stock, and performance share awards.

Share and per share data have been adjusted for prior year periods presented to reflect a two-for-one stock split that was effective September 16, 2016.

The compensation costs related to stock-based awards were as follows:



Fiscal Years Ended October 31	2017		2016		2015
Stock option awards	$	5,496	$	4,606	$	4,704
Restricted stock and restricted stock units	2,300		1,891		1,756
Performance share awards	5,183		3,676		3,964
Unrestricted common stock awards	538		464		412
Total compensation cost for stock-based awards	$	13,517	$	10,637	$	10,836
Related tax benefit from stock-based awards	$	5,001	$	3,936	$	4,009

The number of unissued shares of common stock available for future equity-based grants under the 2010 plan was 5,517,897 as of October 31, 2017. Shares of common stock issued upon exercise or settlement of stock options, restricted stock units, and performance shares are issued from treasury shares.

During fiscal 2017, 2016 and 2015, 11,412, 12,320 and 13,360 shares, respectively, of fully vested unrestricted common stock awards were granted to certain members of the company's Board of Directors as a component of their compensation for their service on the board and are recorded in selling, general and administrative expense in the Consolidated Statements of Earnings.

Stock Option Awards

Under the 2010 plan, stock options are granted with an exercise price equal to the closing price of the company's common stock on the date of grant, as reported by the New York Stock Exchange. Options are generally granted to executive officers, other employees, and non-employee members of the company's Board of Directors on an annual basis in the first quarter of the company's fiscal year. Options generally vest one-third each year over a three-year period and have a ten-year term. Other options granted to certain employees vest in full on the three-year anniversary of the date of grant and have a ten-year term. Compensation expense equal to the grant date fair value is generally recognized for these awards over the vesting period. Stock options granted to executive officers and other employees are subject to accelerated expensing if the option holder meets the retirement definition set forth in the 2010 plan. In that case, the fair value of the options is expensed in the fiscal year of grant because generally the option holder must be employed as of the end of the fiscal year in which the options are granted in order for the options to continue to vest following retirement. Similarly, if a non-employee director has served on the company's Board of Directors for ten full fiscal years or more, the awards vest immediately upon retirement, and therefore, the fair value of the options granted is fully expensed on the date of the grant.

The table below presents stock option activity for fiscal 2017:



	Stock Option Awards		Weighted-Average Exercise Price		Weighted-Average Contractual Life (years)	Aggregate Intrinsic Value
Outstanding as of October 31, 2016	4,879,984		$	20.07	5.3	$	135,697
Granted	554,364		55.82
Exercised	(954,909	)	11.48
Canceled/forfeited	(19,744	)	51.74
Outstanding as of October 31, 2017	4,459,695		$	26.22	5.3	$	163,369
Exercisable as of October 31, 2017	3,331,979		$	19.64	4.3	$	143,960

As of October 31, 2017, there was $3,129 of total unrecognized compensation expense related to unvested stock options. That cost is expected to be recognized over a weighted-average period of 1.99 years.

The table below presents the total market value of stock options exercised and the total intrinsic value of options exercised during the following fiscal years:



Fiscal Years Ended October 31	2017		2016		2015
Market value of stock options exercised	$	58,976	$	61,468	$	27,860
Intrinsic value of options exercised¹	$	48,017	$	41,365	$	18,739


¹	Intrinsic value is calculated as amount by which the stock price at exercise date exceeded the option exercise price.

The fair value of each stock option is estimated on the date of grant using the Black-Scholes valuation method. The expected life is a significant assumption as it determines the period for which the risk-free interest rate, stock price volatility, and dividend yield must be applied. The expected life is the average length of time in which executive officers, other employees, and non-employee directors are expected to exercise their stock options, which is primarily based on historical exercise experience. The company groups executive officers and non-employee directors for valuation purposes based on similar historical exercise behavior. Expected stock price volatilities are based on the daily movement of the company's common stock over the most recent historical period equivalent to the expected life of the option. The risk-free interest rate for periods within the contractual life of the option is based on the U.S. Treasury rate over the expected life at the time of grant. Dividend yield is estimated over the expected life based on the company's historical cash dividends paid, expected future cash dividends and dividend yield, and expected changes in the company's stock price.

The table below illustrates the weighted-average valuation assumptions for options granted in the following fiscal periods:



Fiscal Years Ended October 31	2017			2016			2015
Expected life of option in years	6.02			5.97			5.94
Expected stock price volatility	22.15		%	24.04		%	29.66		%
Risk-free interest rate	2.03		%	1.80		%	1.61		%
Expected dividend yield	1.01		%	1.24		%	1.29		%
Weighted-average fair value at date of grant	$	12.55		$	8.79		$	8.41

Restricted Stock and Restricted Stock Units

Under the 2010 plan, restricted stock and restricted stock unit awards are generally granted to certain employees that are not executive officers. Occasionally, restricted stock or restricted stock unit awards may be granted, including to executive officers, in connection with hiring, mid-year promotions, leadership transition, or retention. Restricted stock and restricted stock unit awards generally vest one-third each year over a three-year period, or vest in full on the three-year anniversary of the date of grant. Such restricted stock and restricted stock unit awards may have performance-based rather than time-based vesting requirements. Compensation expense equal to the grant date fair value, which is equal to the closing price of the company's common stock on the date of grant multiplied by the number of shares subject to the restricted stock and restricted stock unit awards, is recognized for these awards over the vesting period.

Factors related to the company's restricted stock and restricted stock units are as follows:



Fiscal Years Ended October 31	2017		2016		2015
Weighted-average fair value at date of grant	$	66.09	$	41.83	$	33.88
Fair value of restricted stock and restricted stock units vested	$	3,604	$	2,681	$	2,744

The table below summarizes the activity during fiscal 2017 for unvested restricted stock units:



	Restricted Stock Units		Weighted-Average Fair Value at Date of Grant
Unvested as of October 31, 2016	139,480		$	34.51
Granted	43,167		66.09
Vested	(53,709	)	33.14
Forfeited	(4,666	)	37.38
Unvested as of October 31, 2017	124,272		$	45.66

As of October 31, 2017, there was $2,953 of total unrecognized compensation expense related to unvested restricted stock units. That cost is expected to be recognized over a weighted-average period of 2.15 years.

Performance Share Awards

Under the 2010 plan, the company grants performance share awards to executive officers and other employees under which they are entitled to receive shares of the company's common stock contingent on the achievement of performance goals of the company and businesses of the company, which are generally measured over a three-year period. The number of shares of common stock a participant receives can be increased (up to 200 percent of target levels) or reduced (down to zero) based on the level of achievement of performance goals and will vest at the end of a three-year period. Performance share awards are generally granted on an annual basis in the first quarter of the company's fiscal year. Compensation expense is recognized for these awards on a straight-line basis over the vesting period based on the per share fair value as of the date of grant and the probability of achieving each performance goal.

Factors related to the company's performance share awards are as follows:



Fiscal Years Ended October 31	2017		2016		2015
Weighted-average fair value at date of grant	$	54.52	$	38.89	$	32.84
Fair value of performance share awards vested	$	7,018	$	7,454	$	7,989

The table below summarizes the activity during fiscal 2017 for unvested performance share awards:



	Performance Shares		Weighted-Average Fair Value at Date of Grant
Unvested as of October 31, 2016	317,850		$	33.95
Granted	74,800		54.52
Vested	(107,198	)	30.10
Canceled/forfeited	(3,301	)	47.96
Unvested as of October 31, 2017	282,151		$	40.71

As of October 31, 2017, there was $5,108 of total unrecognized compensation expense related to unvested performance share awards. That cost is expected to be recognized over a weighted-average period of 1.67 years.