WITH K AS (SELECT TOTAL_VALUE 
                
              FROM CONVENIENCE
              WHERE SURVEY_YEAR=2019
      AND KIND_CODE='100'
      ORDER BY TOTAL_VALUE)


SELECT ROUND(AVG(TOTAL_VALUE),0) AS SA_MEDIAN
FROM (SELECT TOTAL_VALUE
      FROM K

      ORDER BY TOTAL_VALUE
      LIMIT 2 - (SELECT COUNT(*) FROM K) % 2    -- odd 1, even 2
      OFFSET (SELECT (COUNT(*) - 1) / 2
              FROM K))