13. Net (Loss) Income per Share Attributable to Common Stock

Net (loss) income per share attributable to common stock is calculated using the two-class method. The two-class method is an allocation method of calculating (loss) earnings per share when a company's capital structure includes participating securities that have rights to undistributed earnings. The Company's employees and officers that hold unvested restricted stock are entitled to dividends when the Company pays dividends. The Company's basic net (loss) income per share attributable to common stock is computed by reducing the Company's net (loss) income by the net income allocable to unvested restricted stockholders that have a right to participate in earnings. The Company's employees and officers that hold unvested restricted stock do not participate in losses because they are not contractually obligated to do so. The undistributed earnings are allocated based on the relative percentage of the weighted average unvested restricted stock awards. The basic net (loss) income per share attributable to common stock is computed by dividing the net (loss) income attributable to common stock by the weighted average shares outstanding. The weighted average shares outstanding for the year ended December 31, 2015 was calculated by totaling (i) the product of (x) the weighted shares of Legacy Dawson Common Stock outstanding at the beginning of the year multiplied by (y) the Exchange Ratio, plus (ii) the number of shares associated with awards of Legacy Dawson restricted stock and restricted stock units that vested in conjunction with the Merger, weighted as of February 11, 2015, plus (iii) the number of shares of Legacy TGC Common Stock outstanding immediately prior to the Merger, weighted to reflect that such shares were outstanding from February 11, 2015 until December 31, 2015. The weighted average number of shares outstanding for the three months ended December 31, 2014 and for the years ended September 30, 2014 and 2013 were calculated as if the Merger had occurred at the beginning of the respective period, and the components of the weighted average shares calculation were multiplied by the Exchange Ratio. The Company's dilutive net (loss) income per share attributable to common stock is computed by adjusting basic net (loss) income per share attributable to common stock by diluted income allocable to unvested restricted stock, if any, divided by weighted average diluted shares outstanding. A reconciliation of the basic and diluted (loss) income per share attributable to common stock is as follows:

	Year Ended December 31,			Three Months Ended December 31,			Year Ended September 30,
	2015			2014			2014			2013
	(in thousands, except share and per share data)
Net (loss) income	$	(26,279	)	$	(4,991	)	$	(12,620	)	$	10,480
Income allocable to unvested restricted stock		—			(9	)		(26	)		(136	)

Basic (loss) income attributable to common stock	$	(26,279	)	$	(5,000	)	$	(12,646	)	$	10,344


Reallocation of participating earnings		—			—			—			1

Diluted (loss) income attributable to common stock	$	(26,279	)	$	(5,000	)	$	(12,646	)	$	10,345


Weighted average common shares outstanding:
Basic		20,688,185			14,019,813			14,008,635			13,868,120
Dilutive common stock options and restricted stock units		—			—			—			71,721

Diluted		20,688,185			14,019,813			14,008,635			13,939,841


Basic (loss) income attributable to a share of common stock	$	(1.27	)	$	(0.36	)	$	(0.90	)	$	0.75


Diluted (loss) income attributable to a share of common stock	$	(1.27	)	$	(0.36	)	$	(0.90	)	$	0.74

The Company had a net loss in the year ended December 31, 2015, the three months ended December 31, 2014, and the year ended September 30, 2014. As a result, all stock options and restricted stock units were anti-dilutive and excluded from weighted average shares used in determining the diluted loss attributable to a share of common stock for the respective periods. The following weighted average numbers of stock options and restricted stock units have been excluded from the calculation of diluted loss per share attributable to common stock, as their effect would be anti-dilutive for the year ended December 31, 2015, the three months ended December 31, 2014, and the year ended September 30, 2014:

	Year Ended December 31,		Three Months ended December 31,		Year Ended September 30,
	2015		2014		2014
Stock options		159,561		160,434		162,107
Restricted stock units		126,596		66,405		33,373

Total		286,157		226,839		195,480

There were no weighted average number of stock options or restricted stock units that were anti-dilutive for the year ended September 30, 2013.

The following weighted average shares of unvested restricted stock were included in common stock outstanding as such shares have a nonforfeitable right to participate in any dividends that might be declared and have the right to vote:

	Year Ended December 31,		Three Months Ended December 31,		Year Ended September 30,
	2015		2014		2014		2013
Restricted Stock		46,695		182,160		182,160		182,160