user: Question: What is the average Laps for a grid smaller than 17, and a Constructor of Williams - BMW, driven by Jenson Button?
Columns: ['Driver', 'Constructor', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Michael Schumacher', 'Ferrari', 53.0, '1:27:31.638', 1.0]
SQL:

assistant: SELECT AVG("Laps") FROM "Table" WHERE "Grid" < 17.0 AND "Constructor" = 'Williams - BMW' AND "Driver" = 'Jenson Button';