with ranking as (
    select
        TOTAL_VALUE,
        rank() over (order by TOTAL_VALUE) as rank
    from
        CONVENIENCE
    where
        SURVEY_YEAR = 2019
        and KIND_CODE = '100'
),
counts as (
    select
        count(1) as cnt
    from
        CONVENIENCE
    where
        SURVEY_YEAR = 2019
        and KIND_CODE = '100'
)
select
    round(avg(TOTAL_VALUE)) as SA_MEDIAN
from
    ranking
where
    rank between (select cnt from counts) / 2.0 and (select cnt from counts) / 2.0 + 1