How many episodes aired on 25 october 2012?
CREATE TABLE "red_dwarf_x" (
  "episode_no" real,
  "airdate" text,
  "dave_viewers" real,
  "dave_rank" real,
  "rank_cable" real,
  "dave_ja_vu_viewers" real,
  "total_viewers" real
);
SELECT COUNT("total_viewers") FROM "red_dwarf_x" WHERE "airdate"='25 October 2012';