CREATE TABLE table_203_82 (id NUMBER, "first issued" NUMBER, "design" CLOB, "slogan" CLOB, "serial format" CLOB, "serials issued" CLOB, "notes" CLOB)

what is the average serial format of the arizona license plates ?
SELECT "serial format" FROM table_203_82 GROUP BY "serial format" ORDER BY COUNT(*) DESC LIMIT 1
SELECT "serial format" FROM "table_203_82" GROUP BY "serial format" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY