user: Question: What year has the vehicle of Open wheel and a racing series of Formula One with a Nation of citizenship in Germany.
Columns: ['Year', 'Driver', 'Nation of citizenship', 'Racing series', 'Type of vehicle']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1993.0, 'Nigel Mansell', 'United Kingdom', 'Formula One', 'Open wheel']
SQL:

assistant: SELECT "Year" FROM "Table" WHERE "Type of vehicle" = 'Open wheel' AND "Racing series" = 'Formula One' AND "Nation of citizenship" = 'Germany';