with calc_target as (
select *, count(*) over () as cnt, rank() over (partition by survey_year, kind_code order by total_value desc) as rnk
from convenience
where survey_year = 2019 and kind_code = 100
)
select round(sum(total_value) / count(*)) as SA_MEDIAN
from calc_target
where case when cnt % 2 = 1 then rnk = (cnt + 1) / 2 else rnk = cnt / 2 or rnk = cnt / 2 + 1 end