SELECT ROUND(AVG(CASE WHEN rn IN (counter / 2 + 1, counter / 2 + 1 - (counter % 2 = 0)) THEN TOTAL_VALUE END)) SA_MEDIAN 
FROM (        
  SELECT *,
         ROW_NUMBER() OVER (ORDER BY TOTAL_VALUE) rn,
         COUNT(*) OVER (PARTITION BY SURVEY_YEAR) counter
  FROM CONVENIENCE
  WHERE SURVEY_YEAR='2019'
  and KIND_CODE='100'
)