CREATE TABLE "third_line_series" (
  "airing_date" text,
  "english_title_chinese_title" text,
  "number_of_episodes" real,
  "hd_format" text,
  "highest_average_point_ratings" real,
  "genre" text,
  "official_website" text
);

Question: What was the highest average point rating for a modern suspense show with 21 episodes?
SQL: SELECT SUM("highest_average_point_ratings") FROM "third_line_series" WHERE "genre"='modern suspense' AND "number_of_episodes"=21;