NOTE 5: EARNINGS PER SHARE
We computed basic earnings per share of common stock based on the weighted average number of shares of common stock outstanding during the period. We computed diluted earnings per share of common stock based on the weighted average number of shares of common stock outstanding plus potentially dilutive shares of common stock outstanding during the period.
Potentially dilutive shares of common stock from employee incentive plans are determined by applying the treasury stock method to the assumed exercise of outstanding stock options, the assumed vesting of outstanding RSUs, and the assumed issuance of common stock under the 2006 ESPP. In December 2017, we paid cash to satisfy the conversion of our convertible
debentures due 2035, which we excluded from our diluted earnings per share computation starting in the fourth quarter of 2017 and are no longer dilutive. In November 2019, we issued a notice of redemption for the remaining $372 million of 2009 Debentures with a redemption date of January 9, 2020. Our 2009 Debentures required settlement of the principal amount of the debt in cash upon conversion. Since the conversion premium was paid in cash or stock at our option, we determined the potentially dilutive shares of common stock by applying the treasury stock method. We included our 2009 Debentures in the calculation of diluted earnings per share of common stock in all periods presented because the average market price was above the conversion price.
Potentially dilutive shares of common stock from employee incentive plans are determined by applying the treasury stock method to the assumed exercise of outstanding stock options, the assumed vesting of outstanding RSUs, and the assumed issuance of common stock under the 2006 ESPP. In December 2017, we paid cash to satisfy the conversion of our convertible debentures due 2035, which we excluded from our diluted earnings per share computation starting in the fourth quarter of 2017 and are no longer dilutive. In November 2019, we issued a notice of redemption for the remaining $372 million of 2009 Debentures with a redemption date of January 9, 2020. Our 2009 Debentures required settlement of the principal amount of the debt in cash upon conversion. Since the conversion premium was paid in cash or stock at our option, we determined the potentially dilutive shares of common stock by applying the treasury stock method. We included our 2009 Debentures in the calculation of diluted earnings per share of common stock in all periods presented because the average market price was above the conversion price.
Securities that would have been anti-dilutive are insignificant and are excluded from the computation of diluted earnings per share in all periods presented.
Table:
Years Ended (In Millions, Except Per Share Amounts) | Dec 28, 2019 | Dec 29, 2018 | Dec 30, 2017
Net income available to common stockholders | $21,048 | $21,053 | $9,601
Weighted average shares of common stock outstanding—Basic | 4,417 | 4,611 | 4,701
Dilutive effect of employee incentive plans | 41 | 50 | 47
Dilutive effect of convertible debt | 15 | 40 | 87
Weighted average shares of common stock outstanding—Diluted | 4,473 | 4,701 | 4,835
Earnings per share—Basic | $4.77 | $4.57 | $2.04
Earnings per share—Diluted | $4.71 | $4.48 | $1.99


Question: What is the percentage change of basic earnings per share of common stock from 2018 to 2019?
Answer: 4.38
Calculation: (4.77 - 4.57) / 4.57