user: Question: Who had the lowest laps on a grid smaller than 16 with a time of +21.689?
Columns: ['Rider', 'Manufacturer', 'Laps', 'Time', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Valentino Rossi', 'Yamaha', 22.0, '43:28.841', 2.0]
SQL:

assistant: SELECT MIN("Laps") FROM "Table" WHERE "Grid" < 16.0 AND "Time" = '+21.689';