Table:
|  | 2019 | 2018 | 2017 |
| --- | --- | --- | --- |
| Weighted-average shares outstanding — basic | 25,823 | 28,499 | 30,630 |
| Effect of potentially dilutive securities: |  |  |  |
| Nonvested stock awards and units | 211 | 240 | 182 |
| Stock options | 10 | 40 | 59 |
| Performance share awards | 24 | 28 | 43 |
| Weighted-average shares outstanding — diluted | 26,068 | 28,807 | 30,914 |
| Excluded from diluted weighted-average shares outstanding: |  |  |  |
| Antidilutive | 186 | 150 | 76 |
| Performance conditions not satisfied at the end of the period | 65 | 44 | 53 |
Paragraphs:
15. AVERAGE SHARES OUTSTANDING
Our basic earnings per share calculation is computed based on the weighted-average number of common shares outstanding. Our diluted earnings per share calculation is computed based on the weighted-average number of common shares outstanding adjusted by the number of additional shares that would have been outstanding had the potentially dilutive common shares been issued. Potentially dilutive common shares include nonvested stock awards and units, stock options, and non-management director stock equivalents. Performance share awards are included in the average diluted shares outstanding each period if the performance criteria have been met at the end of the respective periods.
The following table reconciles basic weighted-average shares outstanding to diluted weighted-average shares outstanding in each fiscal year (in thousands):
Question:
How is the basic earnings per share calculation computed?
Answer: Based on the weighted-average number of common shares outstanding