select
    round(avg(TOTAL_VALUE)) AS SA_MEDIAN
from (
    select
        TOTAL_VALUE,
        row_number() over (order by TOTAL_VALUE) as row,
        count(1) over () as total_rows
    from
        CONVENIENCE
    where
        SURVEY_YEAR = 2019
        AND KIND_CODE = '100'
) as sub
where
    row in ((total_rows + 1) / 2, (total_rows + 2) / 2);