The Company calculates its basic income (loss) per share by dividing net income (loss) allocated to common shares outstanding by the weighted average number of common shares outstanding. Unvested shares of restricted stock participate in dividends on the same basis as common shares. As a result, these share-based awards meet the definition of participating securities and the Company applies the two-class method to compute earnings per share. The two-class method is an earnings allocation formula that treats participating securities as having rights to earnings that would otherwise have been available to common stockholders. In periods in which the Company has net losses, the losses are not allocated to participating securities because the participating security holders are not obligated to share in such losses. The following table presents the number of participating securities and earnings allocated to those securities for the years ended December 31, 2018, 2017 and 2016 (in millions):

	2018		2017		2016
Earnings allocated to participating shareholders	$	—	$	—	$	0.5
Number of participating securities		0.9		1.1		1.0

The diluted earnings per share calculations include the effect of the assumed exercise using the treasury stock method for both stock options and unvested restricted stock units, except when the effect would be anti-dilutive. The following table presents the number of common shares used in the calculation of net income (loss) per share from continuing operations for the years ended December 31, 2018, 2017 and 2016 (in millions):

	2018		2017		2016
Weighted-average number of common shares-basic		25.1		24.9		24.5
Dilutive potential common shares		—		—		—
Weighted-average number of common shares-dilutive		25.1		24.9		24.5

The Company had no stock options outstanding at December 31, 2018, 2017 and 2016 and as such had no dilutive effect.