user: Question: What year did the school from Mars Hill, North Carolina join?
Columns: ['Institution', 'Location', 'Founded', 'Type', 'Enrollment', 'Nickname', 'Joined', 'Left', 'Current Conference']
Types: ['text', 'text', 'real', 'text', 'real', 'text', 'real', 'real', 'text']
Sample row: ['Anderson University', 'Anderson, South Carolina', 1911.0, 'Private', 2907.0, 'Trojans', 1998.0, 2010.0, 'SAC']
SQL:

assistant: SELECT "Joined" FROM "Table" WHERE "Location" = 'Mars Hill, North Carolina';