user: Question: For jo siffert, what was the highest grid with the number of laps above 12?
Columns: ['Driver', 'Constructor', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Denny Hulme', 'Brabham - Repco', 15.0, '2:05:55.7', 2.0]
SQL:

assistant: SELECT MAX("Grid") FROM "Table" WHERE "Driver" = 'jo siffert' AND "Laps" > 12.0;