How many different Leagues had average attendance of 3589?
CREATE TABLE "year_by_year" (
  "year" real,
  "division" real,
  "league" text,
  "regular_season" text,
  "playoffs" text,
  "open_cup" text,
  "avg_attendance" real
);
SELECT COUNT("league") FROM "year_by_year" WHERE "avg_attendance"=3589;