16.	Income Per Share Information

The following is a calculation of income per share (dollars in thousands, except share data):

	Year Ended December 31,
		2017		2016		2015
Basic Income Per Share
Net income attributable to CBRE Group, Inc. shareholders	$	691,479	$	571,973	$	547,132
Weighted average shares outstanding for basic income per share		337,658,017		335,414,831		332,616,301
Basic income per share attributable to CBRE Group, Inc. shareholders	$	2.05	$	1.71	$	1.64
Diluted Income Per Share
Net income attributable to CBRE Group, Inc. shareholders	$	691,479	$	571,973	$	547,132
Weighted average shares outstanding for basic income per share		337,658,017		335,414,831		332,616,301
Dilutive effect of contingently issuable shares		3,121,987		2,982,431		3,620,194
Dilutive effect of stock options		3,552		27,301		178,361
Weighted average shares outstanding for diluted income per share		340,783,556		338,424,563		336,414,856
Diluted income per share attributable to CBRE Group, Inc. shareholders	$	2.03	$	1.69	$	1.63

For the years ended December 31, 2017, 2016 and 2015, 621,805, 1,833,941 and 372,020, respectively, of contingently issuable shares were excluded from the computation of diluted income per share because their inclusion would have had an anti-dilutive effect.