SELECT ROUND(AVG(TOTAL_VALUE)) AS SA_MEDIAN
FROM 
(
  SELECT
    TOTAL_VALUE
    FROM
        CONVENIENCE
    WHERE
        SURVEY_YEAR = 2019
        AND KIND_CODE = 100
    ORDER BY
        TOTAL_VALUE
    
    LIMIT 2 - (SELECT COUNT(TOTAL_VALUE) % 2 FROM CONVENIENCE
      WHERE SURVEY_YEAR = 2019 AND KIND_CODE = 100)
    OFFSET (SELECT (COUNT(TOTAL_VALUE)-1) / 2 FROM CONVENIENCE 
      WHERE SURVEY_YEAR = 2019 AND KIND_CODE = 100)
--      ;
);