What is the highest number of maidens when the bowling best was 1/13?
CREATE TABLE "first_class_bowling_statistics" (
  "player" text,
  "matches" real,
  "overs" text,
  "maidens" real,
  "runs" real,
  "wickets" real,
  "average" text,
  "economy" text,
  "5w" real,
  "10w" real,
  "best_bowling" text
);
SELECT MAX("maidens") FROM "first_class_bowling_statistics" WHERE "best_bowling"='1/13';