user: Question: What's the average crowd size that had an away score of 15.17 (107)?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Ground', 'Date', 'Crowd']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'real']
Sample row: ['Geelong', '4.10 (34)', 'Sydney', '6.11 (47)', 'Marrara Oval', 'Friday, 16 February', 8500.0]
SQL:

assistant: SELECT AVG("Crowd") FROM "Table" WHERE "Away team score" = '15.17 (107)';