user: Question: What is the average diff when games played are more than 6?
Columns: ['Club', 'Played', 'Lost', 'Drawn', 'Against', 'Diff.', 'Points']
Types: ['text', 'real', 'real', 'real', 'real', 'real', 'real']
Sample row: ['Brisbane Broncos', 6.0, 0.0, 0.0, 52.0, 218.0, 12.0]
SQL:

assistant: SELECT AVG("Diff.") FROM "Table" WHERE "Played" > 6.0;