with targets as (
    select
        total_value
    from
        convenience
    where
        survey_year = 2019 and
        kind_code = '100'
    order by
        total_value
)
select
    round(avg(total_value)) as SA_MEDIAN
from (
    select total_value
    from targets
    limit
        2 - (select count(*) % 2 from targets)
    offset
        (select (count(*) - 1) / 2 from targets)
)
;