user: Question: What was the lowest Crowd Size for the Home Team of North Melbourne?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['North Melbourne', '7.15 (57)', 'South Melbourne', '8.13 (61)', 'Arden Street Oval', 7730.0, '25 May 1968']
SQL:

assistant: SELECT MIN("Crowd") FROM "Table" WHERE "Home team" = 'North Melbourne';