user: Question: What is the enrollment for the institution that joined in 1987? 
Columns: ['Institution', 'Location', 'Type', 'Joined', 'Enrollment', 'Nickname']
Types: ['text', 'text', 'text', 'real', 'real', 'text']
Sample row: ['Arizona Christian University', 'Phoenix, Arizona', 'Private/Christian', 2012.0, 429.0, 'Firestorm']
SQL:

assistant: SELECT "Enrollment" FROM "Table" WHERE "Joined" = 1987.0;