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 |
| --- | --- | --- | --- | --- |
| Valentino Rossi | Yamaha | 32.0 | 44:04.311 | 2.0 |
| Casey Stoner | Ducati | 32.0 | +13.001 | 1.0 |
| Chris Vermeulen | Suzuki | 32.0 | +26.609 | 8.0 |
| Andrea Dovizioso | Honda | 32.0 | +34.901 | 9.0 |
| Nicky Hayden | Honda | 32.0 | +35.663 | 3.0 |
| Randy de Puniet | Honda | 32.0 | +37.668 | 6.0 |
| Toni Elias | Ducati | 32.0 | +41.629 | 10.0 |
| Ben Spies | Suzuki | 32.0 | +41.927 | 13.0 |
| James Toseland | Yamaha | 32.0 | +43.019 | 5.0 |
| Shinya Nakano | Honda | 32.0 | +44.391 | 12.0 |
| Jamie Hacking | Kawasaki | 32.0 | +46.258 | 17.0 |
| Sylvain Guintoli | Ducati | 32.0 | +55.273 | 14.0 |
| Alex de Angelis | Honda | 32.0 | +55.521 | 16.0 |
| Colin Edwards | Yamaha | 32.0 | +1:02.380 | 7.0 |
| Loris Capirossi | Suzuki | 32.0 | +1:08.207 | 11.0 |
| Marco Melandri | Ducati | 32.0 | +1:10.962 | 15.0 |
| Anthony West | Kawasaki | 31.0 | +1 Lap | 18.0 |
| Jorge Lorenzo | Yamaha | 0.0 | Accident | 4.0 |
Question:
If the manufacturer is Yamaha, and the laps driven were under 32, what's the average of all grid sizes with that criteria?
Answer:
4.0