user: Question: Private/Catholic school's minimum enrollment is?
Columns: ['Institution', 'Location', 'Founded', 'Affiliation', 'Enrollment', 'Team Nickname', 'Primary conference', 'Home Rink']
Types: ['text', 'text', 'real', 'text', 'real', 'text', 'text', 'text']
Sample row: ['Duke University', 'Durham, NC', 1838.0, 'Private/Non-Sectarian', 6496.0, 'Blue Devils', 'Atlantic Coast Conference ( D-I )', 'Triangle Sports Plex']
SQL:

assistant: SELECT MIN("Enrollment") FROM "Table" WHERE "Affiliation" = 'Private/Catholic';