user: Question: What was jack brabham's highest grid when his laps were more than 90?
Columns: ['Driver', 'Constructor', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Jackie Stewart', 'Matra - Ford', 90.0, '2:06:42.08', 2.0]
SQL:

assistant: SELECT MAX("Grid") FROM "Table" WHERE "Driver" = 'jack brabham' AND "Laps" > 90.0;