user: Question: When doeas Mascot of Blue Devils in Gary Froebel School?
Columns: ['School', 'Location', 'Mascot', 'County', 'Joined', 'Previous Conference', 'Left', 'Conference joined']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['East Chicago Washington *', 'East Chicago', 'Senators', '45 Lake', '1927', 'Independents', '1963', 'Northwestern']
SQL:

assistant: SELECT "Joined" FROM "Table" WHERE "Mascot" = 'Blue Devils';