what is the average crowd when the away team is new zealand breakers and the venue is cairns convention centre?
CREATE TABLE "round_9" (
  "date" text,
  "home_team" text,
  "score" text,
  "away_team" text,
  "venue" text,
  "crowd" real,
  "box_score" text,
  "report" text
);
SELECT AVG("crowd") FROM "round_9" WHERE "away_team"='new zealand breakers' AND "venue"='cairns convention centre';