Summarized quarterly results for the two years ended December 31, 2019 and December 31, 2018 are as follows:



	For the Quarter Ended
(in thousands, except per share data)	December 31, 2019				September 30, 2019			June 30, 2019			March 31, 2019
Revenues	$	16,047			$	19,133		$	15,577		$	19,329
Cost of revenues, exclusive of operating expenses shown below	11,104				11,939			12,292			14,108
Other operating expenses	9,630				9,585			7,545			8,776
Operating loss	(4,687		)		(2,391		)	(4,260		)	(3,555		)
Earnings from equity method investments	12,125				14,426			20,935			21,690
Other expenses, net	(1,269		)		(1,517		)	(1,927		)	(2,034		)
Income before income tax expense	6,169				10,518			14,748			16,101
Income tax (benefit) expense	(2,929		)	(1)	6,595			6,634			1,699
Net income	$	9,098			$	3,923		$	8,114		$	14,402
Earnings per common share – basic	$	0.50			$	0.22		$	0.45		$	0.79
Earnings per common share – diluted	$	0.50			$	0.21		$	0.44		$	0.78
Weighted-average number of common shares outstanding
Basic	18,066				18,112			18,172			18,268
Diluted	18,275				18,339			18,377			18,433



	For the Quarter Ended
(in thousands, except per share data)	December 31, 2018				September 30, 2018			June 30, 2018			March 31, 2018
Revenues	$	10,626		(2)	$	5,147		$	4,273		$	3,899
Cost of revenues, exclusive of operating expenses shown below	4,032			(2)	954			704			563
Other operating expenses	9,745			(2), (3)	4,161			5,138			5,048
Operating (loss) income	(3,151		)		32			(1,569		)	(1,712		)
Earnings from equity method investments	16,351				9,715			15,889			12,253
Other expenses, net	(930		)		(313		)	(378		)	(310		)
Income before income tax expense	12,270			(2), (3)	9,434			13,942			10,231
Income tax expense (benefit)	5,272			(4)	3,931			(1,349		)	2,569
Net income	$	6,998			$	5,503		$	15,291		$	7,662
Earnings per common share – basic	$	0.36			$	0.28		$	0.76		$	0.37
Earnings per common share – diluted	$	0.36			$	0.28		$	0.75		$	0.37
Weighted-average number of common shares outstanding
Basic	19,339				19,726			20,062			20,502
Diluted	19,439				19,876			20,195			20,584

(1) During the fourth quarter of 2019, the Company recorded income tax benefit of $2.9 million primarily due to a decrease in current income tax expense compared to current income tax recorded form the nine months ended September 30, 2019. This decrease was primarily due to a decrease in income before income tax expense for the year ended December 31, 2019 compared to the estimated annual income before income tax expense that was used in computing current income tax expense for the nine months ended September 30, 2019.

(2) During the fourth quarter of 2018, the Company completed the Carbon Solutions Acquisition and the operating results for the fourth quarter of 2018 include the operations of Carbon Solutions for the period from December 7 to December 31, 2018. For this period, Carbon Solutions contributed $5.6 million to Revenues, $3.4 million to Cost of Revenue, $2.6 million to Other Operating Expenses and $0.4 million to Loss before income tax expense.

(3) During the fourth quarter of 2018, the Company incurred $3.4 million in transaction costs and $1.1 million in severance charges for executives related to the Carbon Solutions Acquisition that were recorded in Other Operating Expenses.

(4) During the fourth quarter of 2018, the Company recorded income tax expense of $5.3 million primarily due to an increase of $4.5 million to the valuation allowance on its deferred tax assets.