What is the total area with the census ranking of 3,129 of 5,008, and a Population smaller than 460?
CREATE TABLE "westmorland_county_new_brunswick" (
  "official_name" text,
  "status" text,
  "area_km_2" real,
  "population" real,
  "census_ranking" text
);
SELECT COUNT("area_km_2") FROM "westmorland_county_new_brunswick" WHERE "census_ranking"='3,129 of 5,008' AND "population"<460;