user: Question: What was average attendance during week 15?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 4, 1988', 'Cleveland Browns', 'L 6–3', 55654.0]
SQL:

assistant: SELECT AVG("Attendance") FROM "Table" WHERE "Week" = 15.0;