Name the rank on channel for january 21, 2011
CREATE TABLE "united_kingdom" (
  "episode_number_production_number" text,
  "title" text,
  "original_air_date" text,
  "total_viewers_on_fx" text,
  "total_viewers_on_fx" text,
  "total_viewers" text,
  "rank_on_channel" text
);
SELECT "rank_on_channel" FROM "united_kingdom" WHERE "original_air_date"='January 21, 2011';