with tmp as (
    select
        *,
        ROW_NUMBER() OVER(ORDER BY TOTAL_VALUE) num
    from
        CONVENIENCE
    where
        SURVEY_YEAR = '2019' and
        KIND_CODE = '100'
    order by
        TOTAL_VALUE
)

select
    round(avg(TOTAL_VALUE), 0) as SA_MEDIAN
from
    tmp
where
    case
        when (select count(*) from tmp) % 2 = 0 then (select count(*) from tmp) / 2 = num or (select count(*) from tmp) / 2 + 1 = num
        else (select count(*) from tmp) / 2 = num
    end;