What is the highest weight for the Farnley Stakes race?
CREATE TABLE "2001_02_season_as_a_five_year_old" (
  "result" text,
  "date" text,
  "race" text,
  "venue" text,
  "group" text,
  "distance" text,
  "weight_kg" real,
  "jockey" text,
  "winner_2nd" text
);
SELECT MAX("weight_kg") FROM "2001_02_season_as_a_five_year_old" WHERE "race"='farnley stakes';