user: Question: The school of Portage was in what conference previous?
Columns: ['School', 'Location', 'Mascot', 'County', 'Enrollment 08-09', 'IHSAA Class', 'IHSAA Class Football', 'Year Joined', 'Previous Conference']
Types: ['text', 'text', 'text', 'text', 'real', 'text', 'text', 'real', 'text']
Sample row: ['Chesterton', 'Chesterton', 'Trojans', '64 Porter', 1921.0, '4A', '6A', 1970.0, 'Calumet']
SQL:

assistant: SELECT "Previous Conference" FROM "Table" WHERE "School" = 'Portage';