user: Question: What is the lap total for the grid under 15 that retired due to Transmission?
Columns: ['Driver', 'Constructor', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Juan Manuel Fangio', 'Maserati', 77.0, '3:07:46.4', 1.0]
SQL:

assistant: SELECT SUM("Laps") FROM "Table" WHERE "Grid" < 15.0 AND "Time/Retired" = 'Transmission';