with base as (
select
  TOTAL_VALUE
 ,row_number() over(order by main.TOTAL_VALUE asc) as rank
from
  CONVENIENCE as main
where
  SURVEY_YEAR = 2019
  and KIND_CODE = '100'
)
, base2 as (
select
  TOTAL_VALUE
 ,rank
 ,(select count(1) from base) as cnt
from base
)
select
  round(avg(TOTAL_VALUE)) as SA_MEDIAN
from
  base2
where rank between cnt/2.0 and cnt/2.0 + 1