What is the change (%) when the area size (km2) is 247.21?
CREATE TABLE "list" (
  "name" text,
  "municipal_status" text,
  "census_division" text,
  "population_2011" real,
  "population_2006" real,
  "change_pct" text,
  "area_km" text,
  "population_density" text
);
SELECT "change_pct" FROM "list" WHERE "area_km"='247.21';