user: Question: What is the highest number of laps with a 21 start?
Columns: ['Year', 'Start', 'Qual', 'Rank', 'Finish', 'Laps']
Types: ['text', 'text', 'text', 'text', 'text', 'real']
Sample row: ['1948', '21', '127.968', '6', '5', 200.0]
SQL:

assistant: SELECT MAX("Laps") FROM "Table" WHERE "Start" = '21';