user: Question: What's the average crowd size when the venue is Western Oval?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Footscray', '20.14 (134)', 'South Melbourne', '14.11 (95)', 'Western Oval', 22580.0, '17 April 1976']
SQL:

assistant: SELECT AVG("Crowd") FROM "Table" WHERE "Venue" = 'Western Oval';