What is the average attendnace for seasons before 1986, a margin of 6, and a Score of 13.16 (94) – 13.10 (88)?
CREATE TABLE "back_to_back_night_pre_season_winners" (
  "season" real,
  "premier" text,
  "runner_up" text,
  "score" text,
  "venue" text,
  "attendance" real,
  "margin" real
);
SELECT AVG("attendance") FROM "back_to_back_night_pre_season_winners" WHERE "season"<1986 AND "margin"=6 AND "score"='13.16 (94) – 13.10 (88)';