What is the density for the area that is larger than 4,015.6 and a population smaller than 6,178?
CREATE TABLE "administration" (
  "commune" text,
  "area_km_2" real,
  "2002_population" real,
  "density_km_2" real,
  "government_website" text
);
SELECT COUNT("density_km_2") FROM "administration" WHERE "area_km_2">'4,015.6' AND "2002_population"<'6,178';