8. Earnings per share attributable to stockholders

Basic earnings per share (“EPS”) attributable to stockholders was calculated by dividing the net income attributable to stockholders by the weighted average (“WA”) number of common shares outstanding. Diluted EPS attributable to stockholders was calculated by dividing the net income attributable to stockholders after giving effect to outstanding dilutive stock options and PSUs by the WA number of shares outstanding adjusted for all dilutive securities.



	Net income	WA
	attributable to	number		Per share
Three months ended March 31, 2018	stockholders	of shares		amount
Basic	17,138	107,355,381	$	0.16
Effect of dilutive securities:
Share units	-	358,087		-
Stock options	-	930,429		-
Diluted	17,138	108,643,897	$	0.16

8. Earnings per share attributable to stockholders (continued)



	Net income	WA
	attributable to	number		Per share
Three months ended March 31, 2017	stockholders	of shares		amount
Basic	10,377	106,851,595	$	0.10
Effect of dilutive securities:
Share units	27	263,557		-
Stock options	-	673,797		-
Diluted	10,404	107,788,949	$	0.10

In respect of PSUs awarded, performance and market conditions, depending on their outcome at the end of the contingency period, can reduce the number of vested awards to nil or to a maximum of 200% of the number of outstanding PSUs. For the three months ended March 31, 2018, 13,528 share units to purchase common shares were outstanding but excluded from the calculation of diluted EPS attributable to stockholders as they were anti-dilutive (2017: nil). For the three months ended March 31, 2018, stock options to purchase 1,619,141 common shares were outstanding but excluded from the calculation of diluted EPS attributable to stockholders as they were anti-dilutive (2017: nil).