CREATE TABLE table_19418 ("School Year" TEXT, "Class A" TEXT, "Class AA" TEXT, "Class AAA" TEXT, "Class AAAA" TEXT, "Class AAAAA" TEXT)

Name the number of class aa for bridgeport and 1999-2000
SELECT COUNT("Class AA") FROM table_19418 WHERE "Class AAA" = 'Bridgeport' AND "School Year" = '1999-2000'
SELECT COUNT("Class AA") FROM "table_19418" WHERE "Class AAA" = 'Bridgeport' AND "School Year" = '1999-2000'