What is the largest crowd where the home team scored 17.13 (115)?
CREATE TABLE "round_21" (
  "home_team" text,
  "home_team_score" text,
  "away_team" text,
  "away_team_score" text,
  "venue" text,
  "crowd" real,
  "date" text
);
SELECT MAX("crowd") FROM "round_21" WHERE "home_team_score"='17.13 (115)';