user: Question: What is the highest grid for aprilia vehicles, laps over 5, and a retirement finish?
Columns: ['Rider', 'Manufacturer', 'Laps', 'Time', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Nicolas Terol', 'Aprilia', 16.0, '29:51.350', 6.0]
SQL:

assistant: SELECT MAX("Grid") FROM "Table" WHERE "Manufacturer" = 'aprilia' AND "Time" = 'retirement' AND "Laps" > 5.0;