

13.	Net Income (Loss) Per Share Attributable to Sterling Common Stockholders

Basic net income (loss) per share attributable to Sterling common stockholders is computed by dividing net income (loss) attributable to Sterling common stockholders by the weighted average number of common shares outstanding during the period. Diluted net income (loss) per common share attributable to Sterling common stockholders is the same as basic net income (loss) per share attributable to Sterling common stockholders but includes dilutive unvested stock awards and warrants using the treasury stock method. The following table reconciles the numerators and denominators of the basic and diluted per common share computations for net income (loss) attributable to Sterling common stockholders (amounts in thousands, except per share data):



	Years Ended December 31,
	2018		2017		2016
Numerator:
Net income (loss) attributable to Sterling common stockholders	$	25,187	$	11,617	$	(9,238	)
Denominator:
Weighted average common shares outstanding — basic	26,903		26,274		23,140
Shares for dilutive unvested stock	291		438		—
Weighted average common shares outstanding and assumed conversions— diluted	27,194		26,712		23,140
Basic net income (loss) per share attributable to Sterling common stockholders	$	0.94	$	0.44	$	(0.40	)
Diluted net income (loss) per share attributable to Sterling common stockholders	$	0.93	$	0.43	$	(0.40	)

In accordance with the treasury stock method, approximately, 0.4 million shares of unvested stock were excluded from the diluted weighted average common shares outstanding in 2016, respectively, as the Company incurred a loss in that year and the impact of such shares would have been antidilutive.