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:
| Pos | Rider | Manufacturer | Time/Retired | Grid | Points |
| --- | --- | --- | --- | --- | --- |
| 1 | Roberto Rolfo | Honda | 45:14.Ret3 | 8 | 25 |
| 2 | Anthony West | Aprilia | +14.040 | 11 | 20 |
| 3 | Fonsi Nieto | Aprilia | +33.511 | 5 | 16 |
| 4 | Franco Battaini | Aprilia | +54.252 | 3 | 13 |
| 5 | Alex Debón | Honda | +1:06.895 | 13 | 11 |
| 6 | Naoki Matsudo | Yamaha | +1:06.943 | 9 | 10 |
| 7 | Erwan Nigon | Aprilia | +1:13.421 | 12 | 9 |
| 8 | Jaroslav Huleš | Yamaha | +1:22.119 | 10 | 8 |
| 9 | Manuel Poggiali | Aprilia | +1:22.163 | 7 | 7 |
| 10 | Johann Stigefelt | Aprilia | +1:25.303 | 22 | 6 |
| 11 | Toni Elías | Aprilia | +1:41.591 | 1 | 5 |
| 12 | Lukáš Pešek | Yamaha | +2:49.682 | 18 | 4 |
| 13 | Dirk Heidolf | Aprilia | +1 Lap | 17 | 3 |
| 14 | Hugo Marchand | Aprilia | +1 Lap | 19 | 2 |
| 15 | Chaz Davies | Aprilia | +1 Lap | 15 | 1 |
| 16 | Héctor Faubel | Aprilia | +1 Lap | 16 |  |
| 17 | Henk vd Lagemaat | Honda | +2 Laps | 25 |  |
| 18 | Joan Olivé | Aprilia | +3 Laps | 20 |  |
| Ret | Randy de Puniet | Aprilia | Retirement | 4 |  |
| Ret | Christian Gemmel | Honda | Retirement | 23 |  |
| Ret | Eric Bataille | Honda | Retirement | 14 |  |
| Ret | Sebastián Porto | Honda | Retirement | 2 |  |
| Ret | Katja Poensgen | Honda | Retirement | 24 |  |
| Ret | Geoff Hardcastle | Yamaha | Retirement | 26 |  |
| Ret | Alex Baldolini | Aprilia | Retirement | 21 |  |
| Ret | Sylvain Guintoli | Aprilia | Retirement | 6 |  |
Question:
how many riders earned at lease 20 points?
Answer:
2