user: ### NOW ANSWER:
Question: How many people attended the September 21, 1980 game?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 7, 1980', 'at Buffalo Bills', 'L 17–7', 79598.0]
SQL:

assistant: SELECT AVG("Attendance") FROM "Table" WHERE "Date" = 'September 21, 1980';