user: Question: What is the highest enrollment schools that joined the mac in 1997?
Columns: ['Institution', 'Location', 'Nickname', 'Founded', 'Type', 'Enrollment', 'Joined MAC']
Types: ['text', 'text', 'text', 'real', 'text', 'real', 'real']
Sample row: ['Delaware Valley College', 'Doylestown, Pennsylvania', 'Aggies', 1917.0, 'Private/Non-sectarian', 2241.0, 1965.0]
SQL:

assistant: SELECT MAX("Enrollment") FROM "Table" WHERE "Joined MAC" = 1997.0;