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/Retired | Grid |
| --- | --- | --- | --- | --- |
| Alex Barros | Honda | 30.0 | 47:22.404 | 2.0 |
| Valentino Rossi | Honda | 30.0 | +0.230 | 6.0 |
| Max Biaggi | Yamaha | 30.0 | +15.213 | 1.0 |
| Daijiro Kato | Honda | 30.0 | +22.504 | 3.0 |
| Tohru Ukawa | Honda | 30.0 | +35.165 | 7.0 |
| Shinya Nakano | Yamaha | 30.0 | +50.169 | 9.0 |
| Jurgen vd Goorbergh | Honda | 30.0 | +1:03.814 | 15.0 |
| Jeremy McWilliams | Proton KR | 30.0 | +1:05.079 | 8.0 |
| Olivier Jacque | Yamaha | 30.0 | +1:08.312 | 11.0 |
| Norifumi Abe | Yamaha | 30.0 | +1:08.312 | 20.0 |
| John Hopkins | Yamaha | 30.0 | +1:26.241 | 17.0 |
| Andrew Pitt | Kawasaki | 30.0 | +1:27.427 | 18.0 |
| Sete Gibernau | Suzuki | 29.0 | +1 lap | 10.0 |
| Tetsuya Harada | Honda | 29.0 | +1 lap | 22.0 |
| Kenny Roberts, Jr. | Suzuki | 24.0 | Retirement | 14.0 |
| Loris Capirossi | Honda | 19.0 | Accident | 12.0 |
| David García | Proton KR | 13.0 | Retirement | 19.0 |
| Garry McCoy | Yamaha | 6.0 | Accident | 4.0 |
| Nobuatsu Aoki | Proton KR | 1.0 | Accident | 16.0 |
| Régis Laconi | Aprilia | 1.0 | Retirement | 13.0 |
| José Luis Cardoso | Yamaha | 0.0 | Accident | 21.0 |
| Carlos Checa | Yamaha | 0.0 | Accident | 5.0 |
Question:
What is the lowest laps that has a manufacturer of yamaha, and a time/retired of +1:08.312, and a grid less than 20?
Answer:
30.0