How many u.s. viewers (million) have a series # 83?
CREATE TABLE "table1_22570439_1" (
  "series_num" real,
  "season_num" real,
  "episode_title" text,
  "written_by" text,
  "directed_by" text,
  "u_s_viewers_millions" text,
  "original_air_date" text
);
SELECT "u_s_viewers_millions" FROM "table1_22570439_1" WHERE "series_num"=83;