user: Question: What is the average crowd size when the away team scores 7.13 (55)?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Hawthorn', '15.12 (102)', 'Richmond', '17.11 (113)', 'Glenferrie Oval', 18103.0, '12 August 1972']
SQL:

assistant: SELECT AVG("Crowd") FROM "Table" WHERE "Away team score" = '7.13 (55)';