user: Question: Which year did the school with the mascot of the Vikings join?
Columns: ['School', 'Location', 'Mascot', 'County', 'Year Joined', 'Year Left']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Barr Township', 'Montgomery', 'Vikings', '14 Daviess', '1939', 'pre-1958']
SQL:

assistant: SELECT "Year Joined" FROM "Table" WHERE "Mascot" = 'Vikings';