WITH subq AS (
    SELECT
        TOTAL_VALUE
    FROM
        CONVENIENCE
    WHERE
        SURVEY_YEAR = 2019
        AND KIND_CODE = '100' 
    ORDER BY
        TOTAL_VALUE ASC
    LIMIT
        CASE WHEN COUNT(TOTAL_VALUE) % 2 = 0
             THEN 2
             ELSE 1
             END
    OFFSET
        CASE WHEN COUNT(TOTAL_VALUE) % 2 = 0
             THEN COUNT(TOTAL_VALUE) / 2 
             ELSE COUNT(TOTAL_VALUE) / 2 + 1
             END
)

SELECT
    ROUND(AVG(TOTAL_VALUE)) AS SA_MEDIAN
FROM
    subq;