user: Question: What is the average Grid for the Honda CBR1000RR, with 18 laps and a time of +1:12.884?
Columns: ['Rider', 'Bike', 'Laps', 'Time', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Troy Bayliss', 'Ducati 1098 F08', 18.0, '36:11.468', 7.0]
SQL:

assistant: SELECT AVG("Grid") FROM "Table" WHERE "Bike" = 'Honda CBR1000RR' AND "Laps" = 18.0 AND "Time" = '+1:12.884';