For the station opened after 1876 at 604.53km from Wellington, what is the height above sea level?
CREATE TABLE "stations" (
  "station" text,
  "distance_from_wellington" text,
  "height_above_sea_level_m" text,
  "opened" real,
  "closed" text
);
SELECT "height_above_sea_level_m" FROM "stations" WHERE "opened">1876 AND "distance_from_wellington"='604.53km';