user: Question: How big was the crowd when the opponent was Essendon?
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', '21.19 (145)', 'South Melbourne', '12.25 (97)', 'Arden Street Oval', 19437.0, '28 March 1981']
SQL:

assistant: SELECT "Crowd" FROM "Table" WHERE "Away team" = 'Essendon';