user: Question: Who was the opponent during the game that had more than 31891 people in attendance?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 25, 1955', 'at Cleveland Browns', 'W 27-17', 30041.0]
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Attendance" > 31891.0;