Table:
|  |  | Year ended December 31, |  |
| --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 |
| Net income attributable to ON Semiconductor Corporation | $211.7 | $627.4 | $810.7 |
| Basic weighted average common shares outstanding | 410.9 | 423.8 | 421.9 |
| Add: Incremental shares for: |  |  |  |
| Dilutive effect of share-based awards | 1.9 | 4.3 | 5.5 |
| Dilutive effect of convertible notes | 3.2 | 7.8 | 0.9 |
| Diluted weighted average common shares outstanding | 416.0 | 435.9 | 428.3 |
| Net income per common share attributable to ON Semiconductor Corporation: |  |  |  |
| Basic | $0.52 | $1.48 | $1.92 |
| Diluted | $0.51 | $1.44 | $1.89 |
Paragraphs:
Earnings Per Share
Calculations of net income per common share attributable to ON Semiconductor Corporation are as follows (in millions, except per share data):
Basic income per common share is computed by dividing net income attributable to ON Semiconductor Corporation by the weighted average number of common shares outstanding during the period.
To calculate the diluted weighted-average common shares outstanding, the number of incremental shares from the assumed exercise of stock options and assumed issuance of shares relating to RSUs is calculated by applying the treasury stock method. Share-based awards whose impact is considered to be anti-dilutive under the treasury stock method were excluded from the diluted net income per share calculation.
The excluded number of anti-dilutive share-based awards was approximately 0.8 million, 0.6 million and 0.2 million for the years ended December 31, 2019, 2018 and 2017, respectively.
The dilutive impact related to the Company’s 1.00% Notes and 1.625% Notes is determined in accordance with the net share settlement requirements, under which the Company’s convertible notes are assumed to be convertible into cash up to the par value, with the excess of par value being convertible into common stock.
Additionally, if the average price of the Company’s common stock exceeds $ 25.96 per share, with respect to the 1.00% Notes, or $30.70 per share, with respect to the 1.625% Notes, during the relevant reporting period, the effect of the additional potential shares that may be issued related to the warrants that were issued concurrently with the issuance of the convertible notes will also be included in the calculation of diluted weighted-average common shares outstanding.
Prior to conversion, the convertible note hedges are not considered for purposes of the earnings per share calculations, as their effect would be anti-dilutive. Upon conversion, the convertible note hedges are expected to offset the dilutive effect of the 1.00% Notes and 1.625% Notes, respectively, when the stock price is above $18.50 per share, with respect to the 1.00% Notes, and $20.72 per share, with respect to the 1.625% Notes.
Question:
What is the change in Basic weighted average common shares outstanding from year ended December 31, 2018 to 2019?
Answer: 410.9-423.8 = -12.9