CREATE TABLE table_19419 ("School Year" TEXT, "Class A" TEXT, "Class AA" TEXT, "Class AAA" TEXT, "Class AAAA" TEXT, "Class AAAAA" TEXT)

Name the class aa for 1998-99
SELECT "Class AA" FROM table_19419 WHERE "School Year" = '1998-99'
SELECT "Class AA" FROM "table_19419" WHERE "School Year" = '1998-99'