STOCK-BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2022

STOCK-BASED COMPENSATION

Schedule of weighted-average assumptions used to estimate the fair value of options granted

	Three-Months Ended June 30,				Six-Months Ended June 30,
	2022		2021		2022		2021
Dividend yield	0.0	%	0.0	%	0.0	%	0.0	%
Expected volatility	27.8	%	29.0	%	27.7	%	28.9	%
Risk-free interest rate	3.0	%	0.9	%	2.1	%	0.8	%
Expected term	6.2 years		5.9 years		6.0 years		5.8 years

Summary of activities with respect to its stock option plans

				Weighted-
		Weighted-		Average
		Average		Remaining
	Number of	Exercise		Contractual	Aggregate
	Shares	Price Per		Term (in	Intrinsic
Options	(in thousands)	Share		years)	Value
Outstanding at January 1, 2022	13,860	$	48.19	5.1	$	663,148
Granted 01/01/22 – 03/31/22	2,489	$	73.96
Granted 04/01/22 – 06/30/22	8	$	88.05
Exercised	(520)	$	43.50
Cancelled or forfeited	(88)	$	74.32
Outstanding at June 30, 2022	15,749	$	52.29	5.4	$	636,392
Vested and expected to vest in the future at June 30, 2022	15,308	$	51.67	5.3	$	628,074
Exercisable at June 30, 2022	10,569	$	42.99	3.9	$	525,344

Summary of activities with respect to non-vested restricted stock units

		Weighted
	Number of	Average
	Shares (in	Grant-Date
	thousands)	Fair Value
Non-vested at January 1, 2022	910	$	69.02
Granted 01/01/22 - 03/31/221	484	$	71.88
Granted 04/01/22 - 06/30/22	15	$	87.52
Vested	(381)	$	64.24
Forfeited/cancelled	(9)	$	71.54
Non-vested at June 30, 2022	1,019	$	72.42

¹The grant activity for performance share units is recorded based on the target performance level earning 100% of target performance share units. The actual number of performance share units earned could range from 0% to 200% of target depending on the achievement of pre-established performance goals.