We have stock option and stock incentive plans for employees and non-employee Directors that provide for grants of restricted stock awards (“RSAs”), restricted stock units (“RSUs”), performance stock units (“PSUs”), and options to purchase shares of our common stock at exercise prices generally equal to the fair value of such stock at the dates of grant. We also maintain a shareholder-approved Employee Stock Purchase Plan (the “ESPP”) for the benefit of our employees. The ESPP allows eligible employees to purchase common stock on a regular basis at the lower of 85% of the market price at the beginning or end of each offering period.

During the nine months ended September 30, 2020 the Compensation Committee of our Board of Directors (the “Committee”) authorized awards from approved stock incentive plans of RSUs to certain employees, RSAs to non-employee Directors, and RSAs and PSUs to certain Company officers, which, assuming that performance under the PSUs were to be achieved at target levels, together totaled 330,000 shares and had an aggregate grant date market value of $8.2 million. The PSUs granted in 2020 represent the right to receive from 60% to 150% of the target number of shares of common stock. The performance component of PSU awards granted in 2020 is based on attaining specified levels of adjusted EBITDA, as defined in the PSU grant documents, for the 2020 calendar year.

During the nine months ended September 30, 2019 the Committee authorized awards from approved stock incentive plans of RSUs to certain employees, RSAs to non-employee Directors, and RSAs and PSUs to certain Company officers, which, assuming that performance under the PSUs were to be achieved at target levels, together totaled 503,000 shares and had an aggregate grant date market value of $14.9 million. Two types of PSUs were granted in 2019, an annual grant with a one year performance period (“Annual PSU”) and a special Long-Term Incentive Program PSU grant (“LTIP”), which has multiple performance periods over a five year period. If the highest performance thresholds were met, the Annual PSU granted in 2019 represented the right to receive up to 150% of the target number of shares of common stock. The performance component of the Annual PSU awards granted in 2019 was based on attaining specified levels of adjusted earnings before interest, taxes, depreciation, and amortization, (“EBITDA”), as defined in the Annual PSU grant documents, for the 2019 calendar year. The annual PSU granted in 2019 earned approximately 83% of the target number of shares. If the highest performance thresholds were met, the PSUs granted in 2019 under the LTIP represent the right to receive up to 288%, and up to 192% for Mr. Mackin, of the target number of shares of common stock. The performance component of the LTIP awards granted in 2019 is based on attaining specified levels of adjusted revenue growth and gross margin, as defined in the LTIP grant document, for the years 2019 through 2023. The first performance period under the LTIP will not conclude until December 31, 2021.

The Committee authorized, from approved stock incentive plans, grants of stock options to purchase a total of 212,000 and 169,000 shares to certain Company officers during the nine months ended September 30, 2020 and 2019, respectively. The exercise prices of the options were equal to the closing stock prices on their respective grant dates.

Employees purchased common stock totaling 84,000 shares and 61,000 shares in the nine months ended September 30, 2020 and 2019, respectively, through the ESPP. There were no purchases of shares through the ESPP during the three months ended September 30, 2020 and 2019.

The following weighted-average assumptions were used to determine the fair value of options and shares purchased under the ESPP:


	Three Months Ended		Nine Months Ended
	September 30, 2020		September 30, 2020
	Stock Options	ESPP	Stock Options	ESPP
Expected life	N/A	0.5 Years	5 Years	0.5 Years
Expected stock price volatility	N/A	0.83	0.35	0.31
Risk-free interest rate	N/A	0.17%	1.41%	1.57%

The following table summarizes total stock compensation expenses prior to the capitalization of amounts into deferred preservation and inventory costs (in thousands):


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2020		2019		2020		2019
RSA, RSU, and PSU expense	$	1,984	$	2,133	$	6,189	$	5,579
Stock option and ESPP expense		534		487		1,699		1,460
Total stock compensation expense	$	2,518	$	2,620	$	7,888	$	7,039

Included in the total stock compensation expense, as applicable in each period, were expenses related to RSAs, RSUs, PSUs, and stock options issued in each respective year, as well as those issued in prior periods that continue to vest during the period, and compensation related to the ESPP. These amounts were recorded as stock compensation expense and were subject to our normal allocation of expenses to inventory costs and deferred preservation costs. We capitalized $160,000 and $456,000 in the three and nine months ended September 30, 2020, and $158,000 and $458,000 in the three and nine months ended September 30, 2019, of the stock compensation expense into our inventory costs and deferred preservation costs.

As of September 30, 2020 we had total unrecognized compensation costs of $12.5 million related to RSAs, RSUs, and PSUs and $2.5 million related to unvested stock options. As of September 30, 2020 this expense is expected to be recognized over a weighted-average period of 1.9 years for PSUs, 1.8 years for stock options, 1.8 years for RSUs, and 1.2 years for RSAs.