How many codes have a density of 621.68, and a Land area (hectares) larger than 75.28?
CREATE TABLE "references" (
  "urban_area_locality" text,
  "population" real,
  "land_area_hectares" real,
  "density_inh_km" real,
  "code" real
);
SELECT SUM("code") FROM "references" WHERE "density_inh_km"=621.68 AND "land_area_hectares">75.28;