What is the episode number for the episode "a new dimension"?
CREATE TABLE "series_1_2005" (
  "episode_num" text,
  "original_airdate_uk" text,
  "episode_title" text,
  "doctor_who_episode" text,
  "webcast_link" text
);
SELECT "episode_num" FROM "series_1_2005" WHERE "episode_title"='\"A New Dimension\"';