user: Question: What is the size of the team that was previously from Central Indiana conference, and is in IHSSA Class 4A?
Columns: ['School', 'Location', 'Mascot', 'Size', 'IHSAA Class', 'County', 'Year Joined', 'Previous Conference']
Types: ['text', 'text', 'text', 'real', 'text', 'text', 'real', 'text']
Sample row: ['Concord', 'Elkhart, IN', 'Minutemen', 1523.0, '5A', '20 Elkhart', 1967.0, 'Independents']
SQL:

assistant: SELECT "Size" FROM "Table" WHERE "IHSAA Class" = '4A' AND "Previous Conference" = 'Central Indiana';