WITH a AS (
SELECT * FROM HOUSEHOLD
WHERE PERSON_NAME <> '総数'
AND CLASS_NAME <> '総数'
),
b AS(
SELECT *,
  row_number() over (
    partition by
      CLASS_NAME
    order by AMT desc
  ) amt_rank
 FROM a
)
SELECT CLASS_NAME CLASS,
PERSON_NAME PERSON,
AMT HOUSEHOLDS
FROM b 
WHERE amt_rank=1
ORDER BY CLASS_CODE
;