user: Question: Name the IHSAA class with county 18 Delaware and Tigers mascot
Columns: ['School', 'Location', 'Mascot', 'Enrollment', 'IHSAA Class', 'IHSAA Football Class', '# / County']
Types: ['text', 'text', 'text', 'real', 'text', 'text', 'text']
Sample row: ['Muncie Delta', 'Muncie', 'Eagles', 863.0, 'AAA', 'AAAA', '18 Delaware']
SQL:

assistant: SELECT "IHSAA Class" FROM "Table" WHERE "# / County" = '18 Delaware' AND "Mascot" = 'Tigers';