user: Question: What week had an Attendance smaller than 21097?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 30, 1956', 'at Pittsburgh Steelers', 'L 30-13', 27718.0]
SQL:

assistant: SELECT "Week" FROM "Table" WHERE "Attendance" < 21097.0;