WITH RANK AS(
SELECT
    ROW_NUMBER()
        OVER(ORDER BY TOTAL_VALUE DESC) AS RANK
    ,TOTAL_VALUE
FROM
    CONVENIENCE
WHERE
    SURVEY_YEAR = '2019'
    AND KIND_CODE = '100'
)

SELECT
    ROUND(1.0*(SUM(CASE WHEN RANK = (SELECT CEIL(AVG(RANK)) FROM RANK) THEN TOTAL_VALUE ELSE 0 END) + SUM(CASE WHEN RANK = (SELECT FLOOR(AVG(RANK)) FROM RANK) THEN TOTAL_VALUE ELSE 0 END)) /2,0) AS SA_MEDIAN
FROM
    RANK