WITH t1 AS (
    SELECT * FROM convenience
    WHERE survey_year = 2019
      AND kind_code = '100'
)
, t2 AS (
    SELECT
        *,
        row_number() OVER (ORDER BY total_value) AS rn
    FROM t1
)
, t2_inv AS (
    SELECT
        total_value,
        row_number() OVER (ORDER BY total_value DESC) AS rn
    FROM t1
)
, t3 AS (
    SELECT
        t2.rn,
        t2.total_value AS tv2,
        t2_inv.total_value AS tv3
    FROM t2
    JOIN t2_inv ON t2.rn = t2_inv.rn
)
SELECT ROUND(1e0 * (tv2 + tv3) / 2) AS SA_MEDIAN
FROM t3
WHERE rn = (SELECT ROUND(max(rn) / 2) + 1 FROM t3)
LIMIT 10