user: Question: What joined year does Dropped athletics have?
Columns: ['Institution', 'Location', 'Founded', 'Type', 'Enrollment', 'Nickname', 'Joined', 'Left', 'Current Conference']
Types: ['text', 'text', 'real', 'text', 'real', 'text', 'real', 'real', 'text']
Sample row: ['Anna Maria College', 'Paxton, Massachusetts', 1946.0, 'Private', 1432.0, 'AMCats', 1984.0, 2011.0, 'Great Northeast (GNAC)']
SQL:

assistant: SELECT "Joined" FROM "Table" WHERE "Current Conference" = 'Dropped athletics';