pre_text: 19. Net Income per Share The following table presents the calculation of basic and diluted net income per share (in millions, except per-share amounts): Employee equity share options, unvested shares, and similar equity instruments granted and assumed by Cisco are treated as potential common shares outstanding in computing diluted earnings per share. Diluted shares outstanding include the dilutive effect of in-the-money options, unvested restricted stock, and restricted stock units. The dilutive effect of such equity awards is calculated based on the average share price for each fiscal period using the treasury stock method. Under the treasury stock method, the amount the employee must pay for exercising stock options and the amount of compensation cost for future service that has not yet recognized are collectively assumed to be used to repurchase shares.
table: Years Ended July 27, 2019 July 28, 2018 July 29, 2017
table: Net income . $11,621 $110 $9,609
table: Weighted-average shares—basic 4,419 4,837 5,010
table: Effect of dilutive potential common shares 34 44 39
table: Weighted-average shares—diluted . 4,453 4,881 5,049
table: Net income per share—basic . $2.63 $0.02 $1.92
table: Net income per share—diluted $2.61 $0.02 $1.90
table: Antidilutive employee share-based awards, excluded 55 61 136
question: Analyse this data from a financial earnings document. What was the change in the Effect of dilutive potential common shares between 2017 and 2018?