user: Question: What is the average crowd size for Corio 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: ['Richmond', '15.17 (107)', 'St Kilda', '17.4 (106)', 'Punt Road Oval', 27000.0, '2 May 1936']
SQL:

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