user: Question: What is the average grid for marco andretti with a finishing position higher than 19?
Columns: ['Fin. Pos', 'Car No.', 'Driver', 'Team', 'Laps', 'Time/Retired', 'Grid', 'Laps Led', 'Points']
Types: ['real', 'real', 'text', 'text', 'real', 'text', 'real', 'real', 'text']
Sample row: [1.0, 10.0, 'Dan Wheldon', 'Target Chip Ganassi', 200.0, '1:36:56.0586', 4.0, 177.0, '50+3']
SQL:

assistant: SELECT AVG("Grid") FROM "Table" WHERE "Driver" = 'marco andretti' AND "Fin. Pos" > 19.0;