What is the # of candidates of liberal majority with 51 wins and larger number of 2008 in general elections?
CREATE TABLE "general_election_results" (
  "general_election" real,
  "num_of_candidates" real,
  "num_of_seats_won" real,
  "pct_of_popular_vote" text,
  "result" text
);
SELECT AVG("num_of_candidates") FROM "general_election_results" WHERE "result"='liberal majority' AND "num_of_seats_won"=51 AND "general_election">2008;