SELECT
    ROUND(AVG(tmp.TOTAL_VALUE)) AS SA_MEDIAN
FROM
    (SELECT
        *,
        ROW_NUMBER() OVER (
            PARTITION BY 
                SURVEY_YEAR 
            ORDER BY 
                TOTAL_VALUE
        ) AS ROWNUM,
    COUNT(1) OVER(
        PARTITION BY SURVEY_YEAR
        ) AS TOTAL_COUNTS
    FROM
        CONVENIENCE
    WHERE
        KIND_CODE = '100'
    AND
        SURVEY_YEAR = '2019'
    ) AS tmp
WHERE
    tmp.ROWNUM BETWEEN 
        tmp.TOTAL_COUNTS / 2
        AND
        tmp.TOTAL_COUNTS / 2 + 1