user: Question: What was the average of againsts on 21/5/1997?
Columns: ['Opposing Team', 'Against', 'Date', 'Venue', 'Status']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['Córdoba', 21.0, '21/5/1997', 'Chateau Carreras , Córdoba, Argentina', 'Tour Match']
SQL:

assistant: SELECT AVG("Against") FROM "Table" WHERE "Date" = '21/5/1997';