user: Question: What is the average crowd size of Fitzroy's home team?
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', '22.11 (143)', 'South Melbourne', '13.16 (94)', 'MCG', 24307.0, '25 August 1973']
SQL:

assistant: SELECT AVG("Crowd") FROM "Table" WHERE "Home team" = 'Fitzroy';