During what weak of the season was the game played on october 4, 1987?
CREATE TABLE "schedule" (
  "week" real,
  "date" text,
  "opponent" text,
  "result" text,
  "game_site" text,
  "record" text,
  "attendance" text
);
SELECT MAX("week") FROM "schedule" WHERE "date"='October 4, 1987';