SELECT
    TOTAL_VALUE as SA_MEDIAN
FROM
    CONVENIENCE
WHERE
    SURVEY_YEAR = 2019
AND
    KIND_CODE = "100"
ORDER BY
    TOTAL_VALUE
LIMIT 
    2 - (SELECT COUNT(*) FROM CONVENIENCE) % 2    -- odd 1, even 2
OFFSET 
    (SELECT (COUNT(*) - 1) / 2 FROM CONVENIENCE);