What year was the team Club of atlético de san juan fc who plays at hiram bithorn stadium founded.
CREATE TABLE "former_teams" (
  "club" text,
  "home_city" text,
  "stadium" text,
  "founded" real,
  "seasons_in_prsl" text
);
SELECT SUM("founded") FROM "former_teams" WHERE "stadium"='hiram bithorn stadium' AND "club"='atlético de san juan fc';