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:
| Round | Circuit | Date | Pole Position | Fastest Lap | Winning Drivers | Winning Team |
| --- | --- | --- | --- | --- | --- | --- |
| 1.0 | Oulton Park | April 11 | Daniel Brown Stuart Hall | Hector Lester Alan Simonsen | Daniel Brown Stuart Hall | Rollcentre Racing |
| 2.0 | Oulton Park | April 13 | Daniel Brown Stuart Hall | Daniel Brown Stuart Hall | Daniel Brown Stuart Hall | Rollcentre Racing |
| 3.0 | Spa-Francorchamps | May 9 | Daniel Brown Stuart Hall | Hector Lester Alan Simonsen | Gregor Fisken Martin Short | Rollcentre Racing |
| 4.0 | Spa-Francorchamps | May 10 | Hector Lester Alan Simonsen | Aaron Scott Craig Wilkins | Aaron Scott Craig Wilkins | ABG Motorsport |
| 5.0 | Rockingham | May 30 | Oliver Bryant Joe Osborne | Oliver Bryant Joe Osborne | Oliver Bryant Joe Osborne | Barwell Motorsport |
| 6.0 | Rockingham | May 31 | Hector Lester Alan Simonsen | Hector Lester Alan Simonsen | Oliver Bryant Joe Osborne | Barwell Motorsport |
| 7.0 | Knockhill | June 13 | David Jones Godfrey Jones | Hector Lester Stéphane Daoudi | David Jones Godfrey Jones | Team Preci-Spark |
| 8.0 | Knockhill | June 14 | Duncan Cameron Matt Griffin | Gregor Fisken Daniel Brown | Aaron Scott Craig Wilkins | ABG Motorsport |
| 9.0 | Snetterton | July 4 | Daniel Brown Martin Short | Daniel Brown Martin Short | David Jones Godfrey Jones | Team Preci-Spark |
| 10.0 | Snetterton | July 5 | Allan Simonsen Hector Lester | Allan Simonsen Hector Lester | Allan Simonsen Hector Lester | Rosso Verde |
| 11.0 | Donington Park | July 19 | Duncan Cameron Matt Griffin | Hector Lester Alan Simonsen | Alex Mortimer Philip Walker | RPM Motorsport |
| 12.0 | Silverstone | August 16 | Duncan Cameron Matt Griffin | Hector Lester Alan Simonsen | Duncan Cameron Matt Griffin | MTECH Racing |
| 13.0 | Brands Hatch | September 19 | Andrew Howard Jamie Smyth | Alex Mortimer Philip Walker | David Jones Godfrey Jones | Team Preci-Spark |
Question:
On how many different dates was the race at the Silverstone circuit?
Answer:
1.0