BASIC AND DILUTED LOSS PER COMMON SHARE

The following is a reconciliation of weighted average shares outstanding for the years ended December 31, 2018, 2017, 2016, respectively:



	Years Ended December 31,
	2018	2017	2016
Issued common shares at beginning of period	74,366,824	66,205,153	46,519,132
Effect of share options exercised	115,330	—	3,471
Effect of shares issued for settlement of vesting of restricted share units	829,610	831,393	196,242
Effect of shares issued for exercise of share purchase warrants	44,185	—	—
Shares issued for consulting services	122,854	—	—
Effect of shares issued in asset acquisitions	419,986	—	3,184,175
Effect of shares issued for conversion of debentures	323	—	—
Effect of shares issued in public offerings	7,576,288	3,822,561	6,538,038
Weighted average shares outstanding	83,475,400	70,859,107	56,441,058

Basic and diluted loss per share

The calculation of diluted earnings per share after adjustment for the effects of all potential dilutive common shares, calculated as follows:



	Years Ended December 31,
	2018			2017			2016
Net loss to owners of the Company	$	(25,245	)	$	(27,766	)	$	(39,413	)
Basic and diluted weighted average number
of common shares outstanding	83,475,400			70,859,107			56,441,058
Loss per common share	$	(0.30	)	$	(0.39	)	$	(0.70	)

For the three years ended December 31, 2018, 2017 and 2016, 8.23 million, 8.71 million and 10.19 million options and warrants, respectively, and the potential conversion of the Debentures have been excluded from the calculation as their effect would have been anti-dilutive.