user: Question: What is the grid sum with more than 50 laps?
Columns: ['Name', 'Team', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Mark Winterbottom', 'Ford Performance Racing', 50.0, '53:34.4946', 1.0]
SQL:

assistant: SELECT SUM("Grid") FROM "Table" WHERE "Laps" > 50.0;