SELECT
    ROUND(AVG(TOTAL_VALUE)) AS SA_MEDIAN
FROM
    (
        SELECT
            *,
            RANK() OVER(PARTITION BY KIND_CODE ORDER BY TOTAL_VALUE, PF_CODE) AS RANK,
            RANK() OVER(PARTITION BY KIND_CODE ORDER BY TOTAL_VALUE DESC, PF_CODE DESC) AS INV_RANK
        FROM
            CONVENIENCE
        WHERE
            SURVEY_YEAR = 2019
            AND KIND_CODE = 100
    ) AS SUB
WHERE
    ABS(SUB.RANK - SUB.INV_RANK) <= 1