WITH M AS (
 SELECT
 TOTAL_VALUE,
 RANK() OVER (ORDER BY TOTAL_VALUE) RANK
 FROM CONVENIENCE
 WHERE SURVEY_YEAR = 2019 AND KIND_CODE = '100'
), C AS (
 SELECT COUNT(*) CNT FROM M
), MI AS (
 SELECT
  CASE
    WHEN CNT % 2 == 0 THEN CNT / 2
    ELSE ROUND((1.0 * CNT / 2) + 0.5)
  END R
  FROM C
), MA AS (
 SELECT
  CASE
    WHEN CNT % 2 == 0 THEN CNT / 2 + 1
    ELSE ROUND((1.0 * CNT / 2) + 0.5)
  END R
  FROM C
)

SELECT
ROUND((1.0 * (SELECT TOTAL_VALUE FROM M WHERE RANK = (SELECT R FROM MI)) + (SELECT TOTAL_VALUE FROM M WHERE RANK = (SELECT R FROM MA))) / 2) SA_MEDIAN