What was the rating of the episode with an overall ranking of 190?
CREATE TABLE "u_s_nielsen_ratings" (
  "episode_number" real,
  "episode" text,
  "rating" text,
  "share" real,
  "rating_share_18_49" text,
  "viewers_millions" text,
  "rank_overall" text
);
SELECT "rating" FROM "u_s_nielsen_ratings" WHERE "rank_overall"='190';