user: Question: What was the attendance on 21 August 2004?
Columns: ['Date', 'Opponents', 'Result F–A', 'Attendance', 'League position']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['15 August 2004', 'Chelsea', '0–1', 41813.0, '17th']
SQL:

assistant: SELECT "Attendance" FROM "Table" WHERE "Date" = '21 August 2004';