user: Question: When did the away team Footscray score 11.15 (81)?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Richmond', '23.15 (153)', 'St Kilda', '11.15 (81)', 'MCG', 44348.0, '29 July 1972']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Away team score" = '11.15 (81)' AND "Away team" = 'Footscray';