user: Question: What is Mario Domínguez's average Grid?
Columns: ['Driver', 'Team', 'Laps', 'Time/Retired', 'Grid', 'Points']
Types: ['text', 'text', 'real', 'text', 'real', 'real']
Sample row: ['Robert Doornbos', 'Minardi Team USA', 107.0, '1:45:07.617', 15.0, 31.0]
SQL:

assistant: SELECT AVG("Grid") FROM "Table" WHERE "Driver" = 'Mario Domínguez';