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:
| Rider | Manufacturer | Laps | Time | Grid |
| --- | --- | --- | --- | --- |
| Alvaro Bautista | Aprilia | 26.0 | 44:34.257 | 2.0 |
| Marco Simoncelli | Gilera | 26.0 | +7.050 | 1.0 |
| Mika Kallio | KTM | 26.0 | +7.063 | 4.0 |
| Thomas Luthi | Aprilia | 26.0 | +12.998 | 8.0 |
| Hiroshi Aoyama | KTM | 26.0 | +14.666 | 6.0 |
| Yuki Takahashi | Honda | 26.0 | +18.498 | 5.0 |
| Julián Simón | KTM | 26.0 | +26.812 | 11.0 |
| Hector Barbera | Aprilia | 26.0 | +28.012 | 9.0 |
| Hector Faubel | Aprilia | 26.0 | +28.288 | 10.0 |
| Lukas Pesek | Aprilia | 26.0 | +36.966 | 12.0 |
| Aleix Espargaro | Aprilia | 26.0 | +38.296 | 13.0 |
| Alex Baldolini | Aprilia | 26.0 | +52.070 | 14.0 |
| Ratthapark Wilairot | Honda | 26.0 | +1:13.303 | 17.0 |
| Federico Sandi | Aprilia | 26.0 | +1:17.592 | 20.0 |
| Eugene Laverty | Aprilia | 26.0 | +1:21.363 | 21.0 |
| Karel Abraham | Aprilia | 26.0 | +1:26.355 | 16.0 |
| Manuel Poggiali | Gilera | 20.0 | +1:27.438 | 15.0 |
| Imre Toth | Aprilia | 25.0 | +1 lap | 22.0 |
| Doni Tata Pradita | Yamaha | 25.0 | +1 lap | 23.0 |
| Roberto Locatelli | Gilera | 23.0 | Retirement | 19.0 |
| Mattia Pasini | Aprilia | 20.0 | Collision | 3.0 |
| Russell Gómez | Aprilia | 9.0 | Retirement | 24.0 |
| Fabrizio Lai | Gilera | 4.0 | Retirement | 18.0 |
| Alex Debon | Aprilia | 3.0 | Accident | 7.0 |
| Ho Wan Chow | Aprilia | 1.0 | Accident | 25.0 |
Question:
What is the average Laps, when Grid is 15?
Answer:
20.0