What is the highest value under the column goals against?
CREATE TABLE "goalkeeping_leaders" (
  "no" real,
  "player" text,
  "club" text,
  "games_played" real,
  "minutes" real,
  "goals_against" real,
  "ga_average" text,
  "wins" real,
  "loses" real
);
SELECT MAX("goals_against") FROM "goalkeeping_leaders";