Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Driver | Points | Season | Races | Percentage of possible points |
| --- | --- | --- | --- | --- |
| Sebastian Vettel | 392.0 | 2011 | 19.0 | 82.53% |
| Sebastian Vettel | 347.0 | 2013 * | 17.0 | 81.64% |
| Sebastian Vettel | 281.0 | 2012 | 20.0 | 56.20% |
| Fernando Alonso | 278.0 | 2012 | 20.0 | 55.60% |
| Jenson Button | 270.0 | 2011 | 19.0 | 56.84% |
| Mark Webber | 258.0 | 2011 | 19.0 | 54.32% |
| Fernando Alonso | 257.0 | 2011 | 19.0 | 54.11% |
| Sebastian Vettel | 256.0 | 2010 | 19.0 | 53.89% |
| Fernando Alonso | 252.0 | 2010 | 19.0 | 53.05% |
| Mark Webber | 242.0 | 2010 | 19.0 | 50.95% |
Question:
What is the number of races that took place with points of 257?
Answer:
19.0