Basic net income per common share is based on the weighted average number of common shares outstanding and the weighted average minimum number of shares issued upon settlement of the stock purchase contracts issued under the tangible equity units. Diluted net income per common share is based on the weighted average number of common shares outstanding and potentially dilutive shares. The dilutive effect of employee stock-based compensation and shares issuable under the forward equity sale agreement (from the date the Company entered into the forward equity sale agreement to the settlement date) are included in the computation of diluted net income per common share. The dilutive effect of stock-based compensation and shares issuable under the forward equity sale agreement are calculated using the treasury stock method and expected proceeds upon exercise or issuance of the stock-based compensation and settlement of the forward equity sale agreement. The treasury stock method assumes that the proceeds from stock-based compensation and settlement of the forward equity sale agreement are used to purchase the Company’s common stock at the average market price during the period. The following table summarizes the shares, in thousands, used in computing basic and diluted net income per common share:



	Three Months Ended		Nine Months Ended
	September 30,		September 30,
	2022	2021	2022	2021
Average common shares outstanding during the period for basic computation	262,213	258,773	262,089	256,051
Effect of dilutive securities:
Forward equity sale agreement	-	223	-	216
Tangible equity units	-	-	-	-
Employee stock-based compensation	541	441	552	496
Average common shares outstanding during the period for diluted computation	262,754	259,437	262,641	256,763

On May 2, 2022, all of the remaining stock purchase contracts under the tangible equity units were mandatorily settled. For the nine months ended September 30, 2022, the weighted average impact of 3,920,087 shares were included in the basic computation of the average common shares outstanding based on the number of shares that were issued upon settlement of the stock purchase contracts under the tangible equity units. For the three and nine months ended September 30, 2021, the minimum settlement amount of the stock purchase contracts under the tangible equity units of 9,022,040 and 9,067,879 shares, respectively, were considered outstanding for the basic computation of the average common shares outstanding.

The number of outstanding employee stock options that were not included in the diluted earnings per share calculation because the effect would have been anti-dilutive was 81,729 for the three and nine months ended September 30, 2022. For the three and nine months ended September 30, 2021, all of the Company’s outstanding employee stock options were included in the calculations of diluted net income per share as there were no anti-dilutive employee stock options. Additionally, the dilutive effect of