What is the highest goals against when points are larger than 31, the goal difference is smaller than 9, wins are 13, and draws are larger than 6?
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("goals_against") FROM "group_i" WHERE "points">31 AND "goal_difference"<9 AND "wins"=13 AND "draws">6;