select
    dh.pf_code CODE,
    pf.pf_name NAME,
    round(100.0 * sum(
        case 
            when dh.category_code = '120' then dh.amt
            else 0
        end
    ) / sum(
        case
            when dh.category_code = '110' then dh.amt
        end
    ), 1) PERCENTAGE
from
    drink_habits dh
left outer join
    prefecture pf
on
    dh.pf_code = pf.pf_code
group by
    dh.pf_code
order by
    PERCENTAGE desc,
    pf.pf_code desc