There were 25,066 and 14,076 stock grants granted during the six months ended June 30, 2020 and 2019, respectively. The Company recognized $0.5 million of stock-based compensation expense related to stock grants for the three and six months ended June 30, 2020 and 2019, respectively.

During the six months ended June 30, 2019, 37,235 restricted stock units were awarded, 7,518 restricted stock units vested, and 7,978 restricted stock units were forfeited under the Company's Long-Term Incentive Plan, as Amended and Restated (the "Plan"). During the six months ended June 30, 2020, there were no restricted stock units transactions.

The table below shows the Company's stock-based compensation expense related to the restricted stock units for the three and six months ended June 30, 2020 and 2019, respectively, and is included in General and administrative expenses within the Condensed Consolidated Statements of Income:

	Three Months Ended				Six Months Ended
(millions) (unaudited)	June 30, 2020		June 30, 2019		June 30, 2020		June 30, 2019
Stock-based compensation expense	$	0.3	$	0.3	$	0.6	$	0.5

As of June 30, 2020, there was $1.1 million of unrecognized stock-based compensation costs related to the restricted stock units that are expected to be recognized over a weighted average remaining period of approximately 1.4 years.

During the six months ended June 30, 2020 and 2019, the Company granted 96,056 and 125,232 performance share units to certain executives, respectively. During the six months ended June 30, 2020, 1,468 performance share units vested related to certain participating executives being eligible for retirement. No performance share units vested during the six months ended June 30, 2019. During the six months ended June 30, 2020 and 2019, 11,968 and 7,940 performance share units, respectively, were forfeited under the Plan. During the six months ended June 30, 2020, compensation expense related to 290,272 performance share units granted under the Performance-Based Incentive Program was reversed, because the Company no longer expected the required performance targets to be achieved for those awards.

The table below shows the Company's stock-based compensation expense (reduction of expense) related to the Performance-Based Incentive Program for the three and six months ended June 30, 2020 and 2019, respectively, which is included in General and administrative expenses within the Condensed Consolidated Statements of Income:

	Three Months Ended				Six Months Ended
(millions) (unaudited)	June 30, 2020		June 30, 2019		June 30, 2020		June 30, 2019
Stock-based compensation expense	$	0.1	$	0.6	$	(3.1)	$	0.8

As of June 30, 2020, there was $0.1 million of unrecognized compensation expense related to performance share unit awards, which is expected to be recognized over a weighted average period of approximately 0.4 years.