user: Question: What year was the team named the Raiders established?
Columns: ['Institution', 'Location', 'Founded', 'Affiliation', 'Enrollment', 'Team Nickname', 'Primary conference']
Types: ['text', 'text', 'real', 'text', 'real', 'text', 'text']
Sample row: ['Central Washington University', 'Ellensburg, Washington', 1891.0, 'Public', 10400.0, 'Wildcats', 'GNAC ( Division II )']
SQL:

assistant: SELECT "Founded" FROM "Table" WHERE "Team Nickname" = 'Raiders';