select
    TOTAL_VALUE as SA_MEDIAN
from
(
select
    TOTAL_VALUE
    ,row_number() over(partition by '' order by TOTAL_VALUE) as RN
from
    CONVENIENCE
where
    SURVEY_YEAR='2019'
    and KIND_CODE='100'
) SUB
where
    RN=(
    select count(*)
    from CONVENIENCE
    where
        SURVEY_YEAR='2019'
        and KIND_CODE='100')/2