What is the highest score for Black Milk?
CREATE TABLE "list_of_hip_hop_albums_which_received_un" (
  "number" real,
  "artist" text,
  "album" text,
  "average_score" real,
  "number_of_reviews" text
);
SELECT MAX("average_score") FROM "list_of_hip_hop_albums_which_received_un" WHERE "artist"='black milk';