When 12 is the season number how many series numbers are there?
CREATE TABLE "table1_25649467_2" (
  "series_num" real,
  "season_num" real,
  "title" text,
  "director" text,
  "writer_s" text,
  "original_air_date" text
);
SELECT COUNT("series_num") FROM "table1_25649467_2" WHERE "season_num"=12;