user: Question: What is the sum of crowd(s) when North Melbourne is away?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Fitzroy', '10.8 (68)', 'Melbourne', '16.14 (110)', 'Brunswick Street Oval', 23233.0, '18 June 1960']
SQL:

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