What is the highest wins entry with fewer than 51 goals, more than 39 points, and a goal difference smaller than 13?
CREATE TABLE "group_i" (
  "position" real,
  "club" text,
  "played" real,
  "points" real,
  "wins" real,
  "draws" real,
  "losses" real,
  "goals_for" real,
  "goals_against" real,
  "goal_difference" real
);
SELECT MAX("wins") FROM "group_i" WHERE "goals_against"<51 AND "points">39 AND "goal_difference"<13;