How many episodes had a season premiere on December 11, 2010?
CREATE TABLE "seasonal_ratings" (
  "season" real,
  "episodes" real,
  "timeslot_et" text,
  "season_premiere" text,
  "season_finale" text,
  "tv_season" text,
  "rank" text,
  "viewers_in_millions" text
);
SELECT COUNT("episodes") FROM "seasonal_ratings" WHERE "season_premiere"='December 11, 2010';