user: Question: What is the highest week that had a game against the Pittsburgh Steelers with 22597 fans in attendance?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 26, 1954', 'at San Francisco 49ers', 'L 41-7', 32085.0]
SQL:

assistant: SELECT MAX("Week") FROM "Table" WHERE "Attendance" < 22597.0 AND "Opponent" = 'Pittsburgh Steelers';