user: Question: What is the latest year joined with a Conference championships of 5, and an Institution of University of North Carolina?
Columns: ['Institution', 'City', 'State', 'Nickname', 'Joined', 'Conference championships']
Types: ['text', 'text', 'text', 'text', 'real', 'real']
Sample row: ['George Washington University', 'Washington', 'District of Columbia', 'Colonials', 1995.0, 0.0]
SQL:

assistant: SELECT MAX("Joined") FROM "Table" WHERE "Conference championships" = 5.0 AND "Institution" = 'University of North Carolina';