human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Driver, Constructor, Laps, Time/Retired, Grid
###Question: What is the average Laps for a grid smaller than 17, and a Constructor of williams - bmw, driven by jenson button?
gpt
SELECT AVG Laps FROM table WHERE Grid < 17 AND Constructor = williams - bmw AND Driver = jenson button