When united kingdom is the country what is the most recent date?
CREATE TABLE "per_country" (
  "rank" text,
  "country" text,
  "jerseys" real,
  "vuelta_wins" real,
  "points" real,
  "ko_m" real,
  "combo" real,
  "most_recent_cyclist" text,
  "most_recent_date" text,
  "different_holders" real
);
SELECT "most_recent_date" FROM "per_country" WHERE "country"='United Kingdom';