On April 26, 2022, our shareholders approved the Amended and Restated 2015 Omnibus Incentive Plan (the "Amended Plan"), which was adopted by our Board of Directors and became effective on February 24, 2022. The Amended Plan increased the number of shares available for issuance under the 2015 Plan from 1,200,000 to a total of 2,900,000. The Amended Plan allows for the granting of stock, restricted stock, restricted stock units, stock options, performance shares and performance share units. We had 2,213,716 shares available to grant at December 31, 2022.

Compensation expense is determined using the grant date fair value estimated in accordance with the provisions of accounting standards for stock compensation and is recognized over the vesting periods of the individual awards. As of December 31, 2022, total unrecognized compensation expense related to non-vested stock awards was approximately $12 million and is expected to be recognized over a weighted-average period of 1.7 years. Stock-based compensation expense, which is included in Operations and maintenance on the accompanying Consolidated Statements of Income, was as follows for the years ended December 31 (in thousands):

The fair value of restricted stock and restricted stock unit awards equals the market price of our stock on the date of grant.

The shares carry a restriction on the ability to sell the shares until the shares vest. The shares substantially vest over three years, contingent on continued employment. Compensation expense related to the awards is recognized over the vesting period.

A summary of the status of the restricted stock and restricted stock units at December 31, 2022, was as follows:


	Restricted Stock			Weighted-Average Grant Date Fair Value
	(in thousands)
Balance at January 1, 2022		219		$	67.64
Granted		70			69.03
Vested		(94	)		69.64
Forfeited		(16	)		66.03
Balance at December 31, 2022		179		$	67.23

The weighted-average grant-date fair value of restricted stock granted, and the total fair value of shares vested during the years ended December 31, were as follows:


	Weighted-Average Grant Date Fair Value		Total Fair Value of Shares Vested
			(in thousands)
2022	$	69.03	$	6,436
2021	$	65.64	$	5,400
2020	$	69.49	$	6,722

As of December 31, 2022, there was $7.5 million of unrecognized compensation expense related to non-vested restricted stock that is expected to be recognized over a weighted-average period of 1.7 years.

Prior to 2021, certain officers of the Company and its subsidiaries became participants in a market-based performance share award plan. Performance shares are awarded based on our total shareholder return over designated performance periods as measured against a selected peer group. In addition, certain stock price performance must be achieved for a payout to occur. The final value of the performance shares will vary according to the number of shares of common stock that are ultimately granted based upon the actual level of attainment of the performance criteria.

These performance awards are paid 50% in cash and 50% in common stock. The cash portion accrued is classified as a liability and the stock portion is classified as equity. In the event of a change-in-control, performance awards are paid 100% in cash. If it is determined that a change-in-control is probable, the equity portion of $1.4 million at December 31, 2022 would be reclassified as a liability.

The outstanding performance periods at December 31, 2022 were as follows (shares in thousands):


				Possible Payout Range of Target
Grant Date	Performance Period	Target Grant of Shares		Minimum	Maximum
January 1, 2020	January 1, 2020 - December 31, 2022		36	0%	200%

A summary of the status of the Performance Share Plan at December 31, 2022 was as follows:


	Equity Portion					Liability Portion
				Weighted-Average Grant Date					Weighted-Average Fair Value at
	Shares			Fair Value (a)		Shares			December 31, 2022
	(in thousands)					(in thousands)
Performance Shares balance at beginning of period		36		$	68.14		36
Granted		—			—		—
Forfeited		—			—		—
Vested		(18	)		68.72		(18	)
Performance Shares balance at end of period		18		$	81.42		18		$	32.74

(a)

The grant date fair values for the performance shares granted in 2020 were determined by Monte Carlo simulation using a blended volatility of 18%, comprised of 50% historical volatility and 50% implied volatility and the average risk-free interest rate of the three-year United States Treasury security rate in effect as of the grant date.

The weighted-average grant-date fair value of performance share awards granted was as follows in the years ended:


	Weighted Average Grant Date Fair Value
December 31, 2020	$	81.42

Performance plan payouts have been as follows (in thousands):


Performance Period	Year Paid	Stock Issued		Cash Paid		Total Intrinsic Value
January 1, 2019 to December 31, 2021	2022		8	$	519	$	1,038
January 1, 2018 to December 31, 2020	2021		28	$	1,647	$	3,294
January 1, 2017 to December 31, 2019	2020		14	$	1,100	$	2,199

On January 25, 2023, the Compensation Committee of our Board of Directors determined that the Company’s total shareholder return for the January 1, 2020 to December 31, 2022 performance period was at the 26th percentile of its peer group and confirmed a payout equal to 27% of target shares, valued at $0.7 million. The payout was fully accrued at December 31, 2022.

Beginning in 2021, certain officers of the Company, and its subsidiaries, were granted performance share units which have a three-year vesting period, do not have voting rights until vested, and are subject to three specified conditions. A market condition of relative total shareholder return, and two equally weighted performance metrics of average earnings per share and the average cost to serve. The units are paid 100% in common stock should conditions be met and can range from 0% to 200% of the target award. Dividend equivalents are accrued during the vesting period and paid out based on the final number of shares awarded. In the event of participant’s death or retirement at age 55 or older, shares awarded vest on a pro-rata basis over the three-year period.

The fair value of each share unit is based on the Company’s closing price at December 31 of the year prior to the award and a Monte Carlo simulation. The Monte Carlo simulation is used to estimate expected share payout based on the Company’s TSR for a three-year performance period relative to the designated peer group beginning January 1 of the award year.

A performance condition share unit vests at the end of the three-year performance period if the specified performance conditions are achieved. The conditions are based on the Company’s average earnings per share and the average cost to serve. The grant-date fair value for an individual outcome of a performance condition is determined by the closing common share price on the grant date.

The following table summarizes the performance share unit activity for the year ended December 31, 2022:


	Performance Share Units - Market Condition				Performance Share Units - Performance Condition
	Share Units		Weighted-Average Fair Value per Share Unit		Share Units		Weighted-Average Fair Value per Share Unit
Nonvested at January 1, 2022		32,903	$	64.97		21,948	$	61.45
Granted		35,571		74.48		23,718		70.57
Nonvested at December 31, 2022		68,474	$	69.91		45,666	$	66.19

As of December 31, 2022, there was $4.1 million of unrecognized compensation expense related to outstanding performance share/unit plans that is expected to be recognized over a weighted-average period of 1.7 years.