select 
    round(avg(TOTAL_VALUE)) as 'SA_MEDIAN'
from (
    select    
        TOTAL_VALUE
    from
        CONVENIENCE
    where
        SURVEY_YEAR = 2019
        and KIND_CODE = '100'
    order by
        TOTAL_VALUE asc
    limit
        2 - (select count(*) from CONVENIENCE) % 2
    offset
        (select (count(*) - 1) /2 from CONVENIENCE)
)
;