user: Question: what is the lowest grid when the laps is more than 7 and the driver is Rubens Barrichello?
Columns: ['Driver', 'Constructor', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Eddie Irvine', 'Ferrari', 56.0, '1:36:38.494', 2.0]
SQL:

assistant: SELECT MIN("Grid") FROM "Table" WHERE "Laps" > 7.0 AND "Driver" = 'Rubens Barrichello';