CREATE TABLE "new_zealand_ratings" (
  "episode_number" text,
  "episode_name" text,
  "airdate" text,
  "viewers_millions" text,
  "rank_timeslot" text,
  "rank_18_49_night" text
);

Question: what is the total rank on airdate march 30, 2011?
SQL: SELECT COUNT("rank_timeslot") FROM "new_zealand_ratings" WHERE "airdate"='March 30, 2011';