How many million people in the US viewed the episode titled "Behind the Scenes"?
CREATE TABLE "table1_28081876_6" (
  "series_no" real,
  "season_no" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" real,
  "u_s_viewers_millions" text
);
SELECT "u_s_viewers_millions" FROM "table1_28081876_6" WHERE "title"='\"Behind the Scenes\"';