What is the Venue when the Crowd was larger than 11,000 and the Away team score was 7.9 (51)?
CREATE TABLE "round_18" (
  "home_team" text,
  "home_team_score" text,
  "away_team" text,
  "away_team_score" text,
  "venue" text,
  "crowd" real,
  "date" text
);
SELECT "venue" FROM "round_18" WHERE "crowd">'11,000' AND "away_team_score"='7.9 (51)';