user: Question: Which driver has grid value of 18?
Columns: ['Driver', 'Constructor', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Michael Schumacher', 'Benetton - Renault', '67', '1:39:59.044', '3']
SQL:

assistant: SELECT "Driver" FROM "Table" WHERE "Grid" = '18';