WITH BASE AS(
SELECT
	A.TOTAL_VALUE
,	RANK() OVER (ORDER BY A.TOTAL_VALUE) AS RANK
FROM
	CONVENIENCE A
WHERE
	A.SURVEY_YEAR = 2019
AND	A.KIND_CODE = '100'
),
MAX_RANK AS(
SELECT
	MAX(A.RANK) AS RANK_MAX
FROM
	BASE A
),
BASE2 AS(
SELECT
	A.TOTAL_VALUE
,	A.RANK
,	B.RANK_MAX
,	CEIL(B.RANK_MAX / 2) AS MEDIAN1
,	CASE WHEN CEIL(B.RANK_MAX / 2) = TRUNC(B.RANK_MAX / 2) THEN TRUNC(B.RANK_MAX / 2) +1 ELSE TRUNC(B.RANK_MAX / 2) END AS MEDIAN2
FROM
	BASE A
,	MAX_RANK B
)
SELECT
	CEIL(AVG(A.TOTAL_VALUE)) AS SA_MEDIAN
FROM
	BASE2 A
WHERE
	(
		A.RANK = A.MEDIAN1
	OR	A.RANK = A.MEDIAN2
	)