How much Population (2011) has a Land area (km²) larger than 15.69, and a Population density (per km²) larger than 57.3?
CREATE TABLE "northern_villages" (
  "name" text,
  "population_2011" real,
  "population_2006" real,
  "change_pct" real,
  "land_area_km" real,
  "population_density_per_km" real
);
SELECT SUM("population_2011") FROM "northern_villages" WHERE "land_area_km">15.69 AND "population_density_per_km">57.3;