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:
| Date | Race | Race track | Category | Lap length |
| --- | --- | --- | --- | --- |
| July 21, 1946 | 1st Grand Prix des Nations | Circuit des Nations | Grand Prix FIA | km (mi)Switzerland |
| May 2, 1948 | 2nd Grand Prix de Genève | Circuit des Nations | Formula 2 FIA, non-championship | km (mi) |
| May 2, 1948 | 2nd Grand Prix des Nations | Circuit des Nations | Formula 1 FIA, non-championship | km (mi) |
| July 30, 1950 | 3rd Grand Prix de Genève | Circuit des Nations | Formula 2 FIA, non-championship | km (mi) |
| July 30, 1950 | 3rd Grand Prix des Nations | Circuit des Nations | Formula 1 FIA, non-championship | km (mi) |
Question:
What is the Lap Length of the race with a Grand Prix Fia Category?
Answer:
km (mi)Switzerland