Common shares (Tables)

12 Months Ended

Dec. 31, 2018

Summary of Common Shares

thousands of shares At December 31	2018		2017
Authorized		1,100,000		1,100,000
Common shares outstanding		782,565		831,242

Common Share Activities

The company’s common share activities are summarized below:

	Thousands of shares			Millions of dollars
Balance as at January 1, 2016		847,599			1,566
Issued under employee share-based awards		1			-
Purchases at stated value		(1	)		-
Balance as at December 31, 2016		847,599			1,566
Issued under employee share-based awards		2			-
Purchases at stated value		(16,359	)		(30	)
Balance as at December 31, 2017		831,242			1,536
Issued under employee share-based awards		2			-
Purchases at stated value		(48,679	)		(90	)
Balance as at December 31, 2018		782,565			1,446

Calculation of Basic and Diluted Earnings Per Share

The following table provides the calculation of basic and diluted earnings per common share and the dividends declared
by the company on its outstanding common shares:

	2018		2017		2016
Net income (loss) per common share – basic
Net income (loss) (millions of Canadian dollars)		2,314		490		2,165
Weighted average number of common shares outstanding (millions of shares)		807.5		842.9		847.6
Net income (loss) per common share (dollars)		2.87		0.58		2.55
Net income (loss) per common share – diluted
Net income (loss) (millions of Canadian dollars)		2,314		490		2,165
Weighted average number of common shares outstanding (millions of shares)		807.5		842.9		847.6
Effect of employee share-based awards (millions of shares)		2.6		2.8		2.9
Weighted average number of common shares outstanding, assuming dilution (millions of shares)		810.1		845.7		850.5
Net income (loss) per common share (dollars)		2.86		0.58		2.55
Dividends per common share – declared (dollars)		0.73		0.63		0.59