user: Question: What is the smallest crowd with the away 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: ['St Kilda', '10.18 (78)', 'South Melbourne', '13.10 (88)', 'Junction Oval', 18000.0, '22 July 1950']
SQL:

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