user: Question: What's the average Grid for those who spun off after Lap 64?
Columns: ['Driver', 'Constructor', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Damon Hill', 'Williams - Renault', 71.0, '1:49:52.976', 1.0]
SQL:

assistant: SELECT AVG("Grid") FROM "Table" WHERE "Time/Retired" = 'spun off' AND "Laps" > 64.0;