Name the number of area km 2 for population density is 87
CREATE TABLE "area_and_population" (
  "member_state" text,
  "population_in_millions" text,
  "population_pct_of_eu" text,
  "area_km_2" real,
  "area_pct_of_eu" text,
  "pop_density_people_km_2" text
);
SELECT COUNT("area_km_2") FROM "area_and_population" WHERE "pop_density_people_km_2"='87';