select
    vw.class_name   as CLASS
,   vw.person_name  as PERSON
,   vw.amt          as HOUSEHOLDS
from
(
    select
        hh.*
    ,   rank()over(
            partition by
                hh.class_code
            order by
                hh.amt desc
            ) as amt_desc
    from
        HOUSEHOLD hh
    where
        hh.person_code != '1'
    and hh.class_code != '01'
    and hh.amt is not null
)  vw
where
    vw.amt_desc = 1
order by
    vw.class_code