with a as (
select TOTAL_VALUE , ROW_NUMBER() OVER (
                PARTITION BY SURVEY_YEAR
                ORDER BY
                    TOTAL_VALUE
            ) AS ROWNUM
    from CONVENIENCE where SURVEY_YEAR = 2019 and KIND_CODE = 100),
    
b as (select *, (select max(ROWNUM) from a) as m from a )
-- b as (select *, (select 3 from a) as m from a where ROWNUM <= 3)

-- select * from b
select round(avg(TOTAL_VALUE) + 0.001) as SA_MEDIAN from b
where m * 0.5 - 1 <= ROWNUM-1 and ROWNUM-1 <= m * 0.5