what is the 2010 population density for municipio ponce?
CREATE TABLE "puerto_rico" (
  "2012_rank" real,
  "municipio" text,
  "2010_land_area" text,
  "2010_population_density" text,
  "ansi" real,
  "location" text
);
SELECT "2010_population_density" FROM "puerto_rico" WHERE "municipio"='ponce';