Net Income per Common Share

12 Months Ended

Dec. 31, 2019

Basic net income per common share is computed by dividing Net income attributable to SP Plus Corporation by the weighted average number of shares of common stock outstanding during the period. Diluted net income per common share is based upon the weighted average number of shares of common stock outstanding at period end, consisting of incremental shares assumed to be issued upon exercise of stock options and the incremental shares assumed to be issued under performance share and restricted stock unit arrangements, using the treasury-stock method.

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



	Year Ended December 31,
(millions, except share and per share data)	2019		2018		2017
Net income attributable to SP Plus Corporation	$	48.8	$	53.2	$	41.2
Basic weighted average common shares outstanding	22,080,025		22,394,542		22,195,350
Dilutive impact of share-based awards	128,007		212,681		312,938
Diluted weighted average common shares outstanding	22,208,032		22,607,223		22,508,288
Net income per common share
Basic	$	2.21	$	2.38	$	1.86
Diluted	$	2.20	$	2.35	$	1.83

For all years presented above, unvested 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 date.

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.