The maximum number of common units that may be delivered with respect to awards under the Plan is 1,505,000. Generally, the Plan provides for grants of restricted units, unit options, performance awards, phantom units, unit awards, unit appreciation rights, distribution equivalent rights, and other unit-based awards, with various limits and restrictions attached to these awards on a grant-by-grant basis. The Plan is administered by the Board or a committee thereof.

The Board may terminate or amend the Plan at any time with respect to any common units for which a grant has not yet been made. The Board also has the right to alter or amend the Plan or any part of the Plan from time to time, including increasing the number of common units that may be granted, subject to unitholder approval as required by the exchange upon which common units are listed at that time; however, no change in any outstanding grant may be made that would adversely affect the rights of a participant with respect to awards granted to a participant prior to the effective date of such amendment or termination, except that the Board may amend any award to satisfy the requirements of Section 409A of the Internal Revenue Code. The Plan will expire on the tenth anniversary of its approval, when common units are no longer available under the Plan for grants or upon its termination by the Board, whichever occurs first.

	Employees			Directors			Employees
							Phantom
							Performance
							Awards
	Phantom Units			Phantom Units			Initial Target Value
Nonvested at December 31, 2019		—			2,041		$	—
Granted		48,112			12,306			881
Vested		—			(2,041	)		—
Nonvested at December 31, 2020		48,112			12,306		$	881
Granted		37,015			20,787			927
Forfeited		(6,090	)		—			(135	)
Vested		(7,004	)		(16,833	)		—
Nonvested at December 31, 2021		72,033			16,260		$	1,673

In February 2021, the Partnership granted 1,509 phantom units to each of three non-employee directors of the Board as a portion of director compensation. In July 2021, 16,833 phantom units vested, including those granted in February 2021.

In July 2021, the Partnership granted 3,252 phantom units to each of five non-employee directors of the Board. Such awards will vest in July 2022, conditioned upon continuous service as non-employee directors. These awards were accompanied by tandem distribution equivalent rights that entitle the holder to cash payments equal to the amount of unit distributions authorized to be paid to the holders of our common units.

During the second quarter of 2021, 6,090 phantom units and performance-based awards with an initial target value of $0.1 million were forfeited.

During the fourth quarter of 2021, the Partnership granted 37,015 phantom units to employees of the Topper Group. Of these awards, 50% vest ratably over three years through December 31, 2024 and 50% vest upon the employee’s death, disability or retirement. These awards were accompanied by tandem distribution equivalent rights that entitle the holder to cash payments equal to the amount of unit distributions authorized to be paid to the holders of our common units.

During the fourth quarter of 2021, the Partnership granted performance-based awards with an initial target value of $0.9 million. The performance-based awards vest on December 31, 2024 based on attainment of the performance goals set forth in the award agreements. The performance-based awards are weighted 65% for the increase of funds flow from operations per unit (as defined in the award agreements) and 35% for leverage (as defined in the award agreements), with a performance period from January 1, 2022 to December 31, 2024 and the reference period for the year ended December 31, 2021. The payout value for both performance conditions will be interpolated on a linear basis ranging from 0% to 200%, which will then be multiplied by the initial target value to determine the value of the units to be issued. The value of the units will then be divided by the 20-day volume-weighted average closing price of our common units as of the close of trading on the day before the conversion date to determine the actual number of units to be issued.

Since we grant awards to employees of the Topper Group who provide services to us under the Topper Group Omnibus Agreement and non-employee directors of the Board, and since the grants may be settled in cash at the discretion of our Board, unvested phantom units and unvested performance-based awards receive fair value variable accounting treatment. As such, they are measured at fair value at each balance sheet reporting date and the cumulative compensation cost recognized is classified as a liability, which is included in accrued expenses and other current liabilities on the consolidated balance sheet. The balance of the accrual was $1.0 and insignificant at December 31, 2021 and 2020, respectively.

We record equity-based compensation as a component of general and administrative expenses in the statements of income. Equity-based compensation expense was $1.3 million for 2021, $0.1 million for 2020 and $0.9 million for 2019, which includes approximately $0.5 million of expense recognized upon the accelerated vesting of awards concurrent with the GP Purchase.