What is the lowest rank that has university park, pa as the location?
CREATE TABLE "top_10_largest_american_football_stadium" (
  "rank" real,
  "stadium" text,
  "capacity" text,
  "location" text,
  "home_team" text
);
SELECT MIN("rank") FROM "top_10_largest_american_football_stadium" WHERE "location"='university park, pa';