Note 6—Earnings Per Share

Basic earnings per share (“EPS”) is computed by dividing net income attributable to Amphenol Corporation by the weighted average number of common shares outstanding. Diluted EPS is computed by dividing net income attributable to Amphenol Corporation by the weighted average number of common shares and dilutive common shares outstanding, which relates to stock options. Additionally, the prospective adoption of ASU 2016-09 in 2017 had the effect of increasing the Company’s 2017 diluted weighted average common shares outstanding by approximately two million shares. A reconciliation of the basic weighted average common shares outstanding to diluted weighted average common shares outstanding for the years ended December 31, 2017, 2016 and 2015 is as follows:


(dollars and shares in millions, except per share data)	2017		2016		2015
Net income attributable to Amphenol Corporation shareholders	$	650.5	$	822.9	$	763.5
Basic weighted average common shares outstanding		305.7		308.3		309.1
Effect of dilutive stock options		10.8		6.9		7.4
Diluted weighted average common shares outstanding		316.5		315.2		316.5
Earnings per share attributable to Amphenol Corporation shareholders:
Basic	$	2.13	$	2.67	$	2.47
Diluted	$	2.06	$	2.61	$	2.41

Excluded from the computations above were anti-dilutive common shares of 1.6 million, 8.5 million and 6.3 million for the years ended December 31, 2017, 2016 and 2015, respectively.