SELECT AVG(TOTAL_VALUE) AS SA_MEDIAN FROM (SELECT C1.TOTAL_VALUE
    FROM CONVENIENCE AS C1 LEFT OUTER JOIN CONVENIENCE AS C2
    WHERE C1.SURVEY_YEAR='2019' AND C1.KIND_CODE='100'
    GROUP BY C1.TOTAL_VALUE
        HAVING SUM(CASE WHEN C1.TOTAL_VALUE >= C2.TOTAL_VALUE
            THEN 1
            ELSE 0 END ) >= COUNT(*)/2
        AND SUM(CASE WHEN C1.TOTAL_VALUE <= C2.TOTAL_VALUE
            THEN 1
            ELSE 0 END ) >= COUNT(*)/2) AS TMP