In May 2007, our shareholders approved the 2007 Long-Term Incentive Plan (the 2007 LTIP), which authorizes the Compensation Committee of our Board of Directors (the Board) to grant non-qualified stock options and restricted stock awards to employees, directors, consultants or advisors. In May 2016, our shareholders approved an amendment and restatement of the 2007 Long-Term Incentive Plan (the Amended 2007 LTIP) and increased the number of shares that may be issued to a total of 9,315,000 shares. As of December 31, 2021, we had 4,109,524 shares available for future issuance including 933,872 shares that may be issued as restricted stock.

Stock options granted under the Amended 2007 LTIP have an exercise price equal to our stock’s closing market price on the grant date and expire ten years from the grant date. Restricted stock awards granted under the Amended 2007 LTIP are issued at no cost to the grantee. Both stock options and restricted stock awards vest over time depending on an employee’s length of service with the company. Share-based awards to our employees generally vest either five years from the grant date or on a three/five year split vest schedule, where half of the awards vest three years from the grant date and the remainder of the awards vest five years from the grant date. Share-based awards to our non-employee directors vest one year from the grant date.

Restricted stock awards to our employees contain performance-based criteria in addition to the service-based vesting criteria described above. The awards provide for a three-year performance period for the metric to be achieved. If the performance metric fails to be met, it may be extended by one or two years; however, if it is not met by the end of the extended performance period, then all shares of performance-based restricted stock will be immediately forfeited and canceled. For each of the performance-based grants from 2016 through 2019, we achieved the performance condition in the initial three-year performance period. For the performance-based grants in 2020 and 2021, we have concluded that the performance condition is probable to be attained in the initial three-year performance period.


	Shares	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Balance at December 31, 2020	884,059	$	91.49
Granted	44,750	332.91
Less: Exercised	274,253	52.64
Forfeited	2,939	207.30
Balance at December 31, 2021	651,617	$	123.98	4.93	$	288,028,501

Exercisable at December 31, 2021	376,780	$	76.06	3.31	$	184,599,877


	Outstanding Stock Options				Exercisable Stock Options
Range of Exercise Prices	Shares	Weighted Average Remaining Contractual Term (Years)	Weighted Average Exercise Price		Shares	Weighted Average Exercise Price
$ 37.13 to $ 69.85	218,817	2.29	$	59.66	218,817	$	59.66
$ 69.86 to $ 138.03	257,995	5.05	108.93		156,309	97.51
$ 138.04 to $ 515.41	174,805	8.05	226.70		1,654	217.71
	651,617	4.93	$	123.98	376,780	$	76.06


	Year Ended December 31,
(in thousands, except share amounts)	2021		2020		2019
Options exercised	274,253		482,361		640,475
Cash proceeds	$	14,435	$	17,657	$	16,839
Intrinsic value of options exercised	$	118,305	$	116,794	$	97,007
Tax benefits realized	$	29,576	$	29,199	$	24,252


	Year Ended December 31,
(Weighted average)	2021				2020				2019
Expected volatility	27.0		%		20.7		%		21.4		%
Expected term	6.9			years	6.8			years	7.0			years
Risk-free interest rate	1.00		%		1.22		%		2.52		%
Expected dividend yield	1.15		%		1.30		%		1.30		%
Grant date fair value	$	83.05			$	42.52			$	37.75

We calculated expected volatility over the expected term of the awards based on the historical volatility of our common stock. We use weekly price observations for our historical volatility calculation because we believe this provides the most appropriate measurement of volatility given the trading patterns of our common stock. We estimated the expected term based on the vesting period of the awards and our historical exercise activity for awards with similar characteristics. The risk-free interest rate is based on the U.S. Treasury zero-coupon issues with a remaining term approximating the expected term of the option. We determined the expected dividend yield based on the dividends we anticipate paying over the expected term.

For purposes of recognizing share-based compensation expense, we ratably expense the estimated fair value of employee stock options over the options’ requisite service period. The requisite service period for our share-based awards is either the vesting period, or if shorter, the period from the grant date to the date the employee becomes eligible to retire under our share-based award agreements. We recognize compensation cost for awards with graded vesting using the graded vesting recognition method. We estimate a forfeiture rate to calculate our share-based compensation expense for our share-based awards based on an analysis of actual forfeitures. We continue to evaluate the appropriateness of the forfeiture rate based on actual forfeiture experience, analysis of employee turnover, and other factors.

At December 31, 2021, the unamortized compensation expense related to stock option awards totaled $3.6 million. We anticipate recognizing this expense over a weighted average period of 2.8 years.


	Shares	Weighted Average Grant Date Fair Value
Balance unvested at December 31, 2020	291,704	$	153.12
Granted (at market price) (1)	40,597	335.80
Less: Vested	69,069	115.88
Forfeited	2,494	295.73
Balance unvested at December 31, 2021	260,738	$	190.26

At December 31, 2021, the unamortized compensation expense related to the restricted stock awards totaled $14.5 million. We anticipate recognizing this expense over a weighted average period of 3.0 years.

The table below presents the total number of restricted stock awards that vested for the past three years and the related fair value of those awards (in thousands, except share amounts):

We maintain the Pool Corporation Amended and Restated Employee Stock Purchase Plan (the ESPP), which was last approved by the Board and our stockholders in 2016. Under the ESPP, employees who meet minimum age and length of service requirements may purchase stock at 85% of the lower of:

No more than 956,250 shares of our common stock may be issued under the ESPP. For the two six month offering periods in each of the last three years, our employees purchased the following aggregate number of shares:

The grant date fair value for the most recent ESPP purchase period ended July 31, 2021 was $121.82 per share. Share-based compensation expense related to our ESPP was $0.8 million in 2021, $0.7 million in 2020 and $0.4 million in 2019.