Away team Swindon Town had a Tie no listing of Replay with what as an Attendance?
CREATE TABLE "fifth_round_proper" (
  "tie_no" text,
  "home_team" text,
  "score" text,
  "away_team" text,
  "attendance" text
);
SELECT "attendance" FROM "fifth_round_proper" WHERE "tie_no"='replay' AND "away_team"='swindon town';