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:
| Year | Formula | Driver | Constructor | Location | Report |
| --- | --- | --- | --- | --- | --- |
| 1902.0 | Grand Prix | Charles Jarrott | Panhard 70 | Bastogne | Report |
| 1903.0 | Grand Prix | Pierre de Crawhez | Panhard 70 | Bastogne | Report |
| 1904.0 | Grand Prix | George Heath | Panhard 70 | Bastogne | Report |
| 1905.0 | Grand Prix | Victor Hémery | Darracq | Bastogne | Report |
| 1906.0 | Grand Prix | Arthur Duray | Lorraine-Dietrich | Bastogne | Report |
| 1907.0 | Grand Prix | Pierre de Caters | Mercedes-Benz | Bastogne | Report |
| 1907.0 | Kaiserpreis | John Moore-Brabazon | Minerva | Bastogne | Report |
Question:
How many years had a formula of Grand Prix?
Answer:
6.0