What is the average attendance for games against the Pittsburgh Steelers when the opponents scored more than 0 points?
CREATE TABLE "schedule" (
  "game" real,
  "date" text,
  "opponent" text,
  "result" text,
  "bills_points" real,
  "opponents" real,
  "record" text,
  "attendance" real
);
SELECT AVG("attendance") FROM "schedule" WHERE "opponent"='pittsburgh steelers' AND "opponents">0;