When beauval is the name what is the lowest population of 2011?
CREATE TABLE "northern_villages" (
  "name" text,
  "population_2011" real,
  "population_2006" real,
  "change_pct" text,
  "land_area_km" text,
  "population_density_per_km" text
);
SELECT MIN("population_2011") FROM "northern_villages" WHERE "name"='Beauval';