select
round(avg(total_value)) as SA_MEDIAN
from(
select
total_value,
row_number() over(
partition by survey_year,kind_code order by total_value desc) as val_rank,
count(1) over(partition by survey_year,kind_code) as total_count
from convenience
where survey_year = 2019
and kind_code = '100')
where val_rank between total_count * 1/2 and total_count * 1/2+1