Name the least 10,000+ places for louisville
CREATE TABLE "metropolitan_areas" (
  "rank" real,
  "metropolitan_area" text,
  "principal_city" text,
  "10_000_places" real,
  "densest_incorporated_place" text,
  "density" text
);
SELECT MIN("10_000_places") FROM "metropolitan_areas" WHERE "principal_city"='Louisville';