CREATE TABLE table_23409 ("No. overall" TEXT, "No. in series" FLOAT, "Family/families" TEXT, "Location ( s ) " TEXT, "Original air date" TEXT)

Name the number of families for uk30
SELECT COUNT("Family/families") FROM table_23409 WHERE "No. overall" = 'UK30'
SELECT COUNT("Family/families") FROM "table_23409" WHERE "No. overall" = 'UK30'