What is the average change to have a land area of 546.74 and a population density greater than 0.5?
CREATE TABLE "list" (
  "rural_municipality_rm" text,
  "rm_no" text,
  "sarm_div_no" text,
  "census_div_no" text,
  "population_2011" real,
  "population_2006" real,
  "change_pct" real,
  "land_area_km" real,
  "population_density_per_km" real
);
SELECT AVG("change_pct") FROM "list" WHERE "land_area_km"=546.74 AND "population_density_per_km">0.5;