SELECT AVG(TOTAL_VALUE) AS SA_MEDIAN FROM (
    SELECT TOTAL_VALUE FROM CONVENIENCE
        WHERE 
            SURVEY_YEAR = 2019
            AND KIND_CODE = 100
        ORDER BY TOTAL_VALUE
        LIMIT 2 - (
        SELECT COUNT(*) % 2 FROM CONVENIENCE
            WHERE 
                SURVEY_YEAR = 2019
                AND KIND_CODE = 100
        )
        OFFSET (
            SELECT (COUNT(*) - 1) / 2 FROM CONVENIENCE
                WHERE 
                    SURVEY_YEAR = 2019
                    AND KIND_CODE = 100
        )
)