WITH 
PRE_MEDIAN AS (
    SELECT
        CV1.TOTAL_VALUE
    FROM
        CONVENIENCE CV1
        INNER JOIN CONVENIENCE CV2
            ON CV2.SURVEY_YEAR = 2019
            AND CV2.KIND_CODE = '100'
    WHERE
        CV1.SURVEY_YEAR = 2019
        AND CV1.KIND_CODE = '100'
    GROUP BY
        CV1.TOTAL_VALUE
    HAVING
        CASE MOD(COUNT(*), 2)
            WHEN 0 THEN 
                        SUM(CASE WHEN CV2.TOTAL_VALUE >= CV1.TOTAL_VALUE THEN 1 ELSE 0 END) >= COUNT(*) / 2
                        AND SUM(CASE WHEN CV2.TOTAL_VALUE <= CV1.TOTAL_VALUE THEN 1 ELSE 0 END) >= COUNT(*) / 2 
            ELSE  SUM(CASE WHEN CV2.TOTAL_VALUE >= CV1.TOTAL_VALUE THEN 1 ELSE 0 END) >= COUNT(*) / 2
                    AND SUM(CASE WHEN CV2.TOTAL_VALUE <= CV1.TOTAL_VALUE THEN 1 ELSE 0 END) >= COUNT(*) / 2
        END
)

SELECT
    ROUND(AVG(TOTAL_VALUE)) AS SA_MEDIAN
FROM
    PRE_MEDIAN