SELECT
    ROUND(AVG(TOTAL_VALUE)) AS SA_MEDIAN
FROM
(
    SELECT
        TOTAL_VALUE,
        ROW_NUMBER() OVER (ORDER BY TOTAL_VALUE) AS ROW_NUM,
        COUNT(*) OVER () AS TOTAL_COUNT
    FROM CONVENIENCE 
    WHERE SURVEY_YEAR = 2019 and KIND_CODE = '100'
    ORDER BY TOTAL_VALUE
)
WHERE ROW_NUM IN (((TOTAL_COUNT + 1) / 2), ((TOTAL_COUNT + 2) / 2))