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 | Constructor | Laps | Time/Retired | Grid |
| --- | --- | --- | --- | --- |
| Jacky Ickx | Ferrari | 70.0 | 1:56:20.0 | 1.0 |
| Pedro Rodriguez | BRM | 70.0 | +7.99 | 2.0 |
| Clay Regazzoni | Ferrari | 69.0 | + 1 Lap | 4.0 |
| Ronnie Peterson | March - Ford | 68.0 | + 2 Laps | 13.0 |
| John Surtees | Surtees - Ford | 68.0 | + 2 Laps | 7.0 |
| Jo Siffert | BRM | 68.0 | + 2 Laps | 8.0 |
| Howden Ganley | BRM | 66.0 | + 4 Laps | 9.0 |
| Gijs Van Lennep | Surtees - Ford | 65.0 | + 5 Laps | 21.0 |
| Jean-Pierre Beltoise | Matra | 65.0 | + 5 Laps | 11.0 |
| Graham Hill | Brabham - Ford | 65.0 | + 5 Laps | 16.0 |
| Jackie Stewart | Tyrrell - Ford | 65.0 | + 5 Laps | 3.0 |
| Denny Hulme | McLaren - Ford | 63.0 | + 7 laps | 14.0 |
| Henri Pescarolo | March - Ford | 62.0 | Not Classified | 15.0 |
| Skip Barber | March - Ford | 60.0 | Not Classified | 24.0 |
| Peter Gethin | McLaren - Ford | 60.0 | Not Classified | 23.0 |
| Alex Soler-Roig | March - Ford | 57.0 | Engine | 17.0 |
| Tim Schenken | Brabham - Ford | 39.0 | Suspension | 19.0 |
| François Cevert | Tyrrell - Ford | 29.0 | Accident | 12.0 |
| Rolf Stommelen | Surtees - Ford | 19.0 | Disqualified | 18.0 |
| Reine Wisell | Lotus - Ford | 17.0 | Disqualified | 4.0 |
| Nanni Galli | March - Alfa Romeo | 7.0 | Accident | 20.0 |
| Mario Andretti | Ferrari | 5.0 | Fuel Pump | 16.0 |
| Dave Walker | Lotus - Pratt & Whitney | 5.0 | Accident | 22.0 |
| Chris Amon | Matra | 2.0 | Spun off | 5.0 |
Question:
what is the most laps with a grid of 20?
Answer:
7.0