user: Question: What year did the University of Pittsburgh school join the hockey league? 
Columns: ['Institution', 'Location', 'Team Nickname', 'Joined TSCHL', 'Home Arena', 'Capacity', 'Team Website']
Types: ['text', 'text', 'text', 'real', 'text', 'real', 'text']
Sample row: ['University of Akron', 'Akron, OH', 'Zips', 2010.0, 'Center Ice Sports Complex', 900.0, 'Zips Hockey']
SQL:

assistant: SELECT "Joined TSCHL" FROM "Table" WHERE "Institution" = 'University of Pittsburgh';