•2004 Employee Stock Purchase Plan (the "2004 Purchase Plan"): The 2004 Purchase Plan permits eligible employees to purchase common stock on favorable terms via payroll deductions of up to 15% of the employee's cash compensation, subject to certain share and statutory dollar limits. Two overlapping offering periods commence during each calendar year, on each February 15 and August 15 or such other periods or dates as determined by the Compensation Committee from time to time, and the offering periods last up to 24 months with a purchase date every 6 months. The price of each share purchased is 85% of the lower of

a) the fair value per share of common stock on the last trading day before the commencement of the applicable offering period or b) the fair value per share of common stock on the purchase date.

•2020 Equity Incentive Plan: In 2020, both our Board of Directors and our stockholders approved the 2020 Equity Plan, which provides for the grant of stock options, including incentive stock options and non-qualified stock options, stock appreciation rights, RSAs, RSUs, other stock-based incentive awards, dividend equivalents, and cash-based incentive awards. The 2020 Equity Plan's awards may be granted to employees, non-employee members of the Board and consultants. Equity awards granted under the 2020 Equity Incentive Plan generally vest over four years. The maximum numbers of shares of our common stock available for issuance under the 2020 Equity Plan is equal to the sum of 4.0 million shares and the shares transferred from the 2000 Equity Incentive Plan.

The Equity compensation plans are administered by the Talent, Culture and Compensation Committee of the Board of Directors (the "Compensation Committee"), and the Compensation Committee may terminate or amend these plans, with approval of the stockholders as may be required by applicable law, at any time. As of December 31, 2022, shares reserved and available for issuance under the equity compensation plans are as follows:

Since 2008, we primarily grant RSUs to our employees, including executives and non-employee directors, in lieu of stock options. We generally grant RSUs that have a service condition only or have both a service and performance condition. Each RSU is not considered issued and outstanding and does not have voting rights until it is converted into one share of our common stock upon vesting. RSUs activity is summarized as follows:


	Number of Shares Outstanding	Weighted Average Grant Date Fair Value per Share		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value (1) (Dollars in Thousands)
RSUs outstanding, December 31, 2019	1,312,725	$	411.99
RSUs granted	695,383	596.80

RSUs released, vested	(606,250)	426.03
Special distribution shares released	(722)	264.57
RSUs canceled	(63,502)	457.91

RSUs outstanding, December 31, 2020	1,337,634	499.60
RSUs granted	776,628	679.59

RSUs released, vested	(633,466)	505.40
Special distribution shares released	(34)	297.03
RSUs canceled	(123,168)	561.34

RSUs outstanding, December 31, 2021	1,357,594	594.27
RSUs granted	912,249	661.43

RSUs released, vested	(668,733)	576.62

RSUs canceled	(155,418)	624.98

RSUs outstanding, December 31, 2022	1,445,692	$	641.51	1.26	$	946,971

The total fair value of RSUs vested and released during the years ended December 31, 2022, 2021 and 2020 was $462.0 million, $472.9 million and $417.0 million, respectively.


	2022		2021		2020
Weighted-average purchase price per share	$	568.29	$	467.59	$	371.71
Weighted average grant-date fair value per share of shares purchased	$	202.61	$	138.80	$	114.08
Number of shares purchased	143,515		166,023		167,113

We use the Black-Scholes option-pricing model to determine the fair value of shares under the 2004 Purchase Plan with the following assumptions during the years ended December 31:


	2022		2021		2020
Range of dividend yield	1.48% - 1.55%		1.58 - 1.77%		1.94 - 2.08%
Range of risk-free interest rate	0.72% - 3.06%		0.01 - 0.21%		0.10 - 1.55%
Range of expected volatility	25.73% - 37.20%		25.54 - 41.24%		19.28 - 51.93%
Weighted-average expected volatility	30.34	%	34.08	%	32.94	%
Weighted average expected life (in years)	1.06		1.18		1.36

The following table presents, by operating expense, our stock-based compensation expense recognized in our consolidated statement of operations for the years ended December 31 (in thousands):


	2022		2021		2020
Cost of revenues	$	45,028	$	38,438	$	32,893
Sales and marketing	82,794		79,144		72,895
General and administrative	276,161		246,192		205,232
Total	$	403,983	$	363,774	$	311,020

Our stock-based compensation recognized in the consolidated statement of operations was comprised of the following types of equity awards for the years ended December 31 (in thousands):


	2022		2021		2020

RSUs	$	359,952	$	330,077	$	289,426
RSAs(1)	9,793		10,067		8,289
Employee stock purchase plan	34,238		23,630		13,305
Total	$	403,983	$	363,774	$	311,020

During the years ended December 31, 2022, 2021 and 2020, we capitalized $46.3 million, $27.7 million and $20.3 million, respectively, of stock-based compensation expense as construction in progress in property, plant and equipment.

As of December 31, 2022, the total stock-based compensation cost related to unvested equity awards not yet recognized, net of estimated forfeitures, totaled $694.7 million which is expected to be recognized over a weighted-average period of 2.18 years.