Net Income per Common Share

Basic net income per share is computed by dividing net income by the weighted daily average number of shares of common stock outstanding during the period. Diluted net income per share is based upon the weighted daily average number of shares of common stock outstanding for the period plus dilutive potential common shares, including stock options and restricted stock units using the treasury-stock method.

A reconciliation of the weighted average basic common shares outstanding to the weighted average diluted common shares outstanding is as follows:



	Three Months Ended				Nine Months Ended
(millions, except share and per share data) (unaudited)	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Net income attributable to SP Plus Corporation	$	11.2	$	7.0	$	33.4	$	13.5
Basic weighted average common shares outstanding	22,203,023		22,208,139		22,186,556		22,293,776
Dilutive impact of share-based awards	320,013		288,972		314,822		278,157
Diluted weighted average common shares outstanding	22,523,036		22,497,111		22,501,378		22,571,933
Net income per common share
Basic	$	0.51	$	0.31	$	1.51	$	0.60
Diluted	$	0.50	$	0.31	$	1.48	$	0.60

For the three and nine months ended September 30, 2017 and 2016, performance share units were excluded from the computation of weighted average diluted common share outstanding because the number of shares ultimately issuable is contingent on the Company's performance goals, which were not achieved as of the reporting dates.

There are no additional securities that could dilute basic earnings per share in the future that were not included in the computation of diluted earnings per share, other than those disclosed.

Adoption of ASU 2016-09

There was no significant impact to diluted weighted average shares outstanding for purposes of calculating net income per common share-diluted as a result of adopting ASU 2016-09. Refer to Note 1. Significant Accounting Policies and Practices for additional information on the impact of adopting ASU 2016-09 to the Company.