DECLARE @QTD INT, @MEDIAN_INDEX_1 AS INT, @MEDIAN_INDEX_2 AS INT, @MEDIAN_VALUE FLOAT

SET @QTD = (SELECT COUNT(LAT_N) FROM STATION)

IF @QTD % 2 <> 0 
  BEGIN
    SET @MEDIAN_INDEX_1 = (@QTD + 1) / 2
    SET @MEDIAN_INDEX_2 = @MEDIAN_INDEX_1
    SET @MEDIAN_VALUE = (
      SELECT LAT_N FROM (
        SELECT LAT_N, ROW_NUMBER() OVER(ORDER BY LAT_N ASC) AS RN FROM STATION
      ) AS A WHERE RN = @MEDIAN_INDEX_1
    )
  END
ELSE
  BEGIN
    SET @MEDIAN_INDEX_1 = @QTD / 2
    SET @MEDIAN_INDEX_2 = @MEDIAN_INDEX_1 + 1
    SET @MEDIAN_VALUE = (
      SELECT AVG(LAT_N) FROM (
        SELECT LAT_N, ROW_NUMBER() OVER(ORDER BY LAT_N ASC) AS RN FROM STATION
      ) AS A WHERE RN IN (@MEDIAN_INDEX_1, @MEDIAN_INDEX_2)
    )
  END

SELECT CAST(ROUND(@MEDIAN_VALUE, 4, 0) AS DECIMAL(38, 4))