user: Question: How many different dates are there for founded teams for the venue of champion window field?
Columns: ['Club', 'Sport', 'Founded', 'League', 'Venue']
Types: ['text', 'text', 'real', 'text', 'text']
Sample row: ['Cincinnati Bengals', 'Football', 1968.0, 'National Football League , AFC', 'Paul Brown Stadium']
SQL:

assistant: SELECT COUNT("Founded") FROM "Table" WHERE "Venue" = 'champion window field';