What is the average new council number when the election result is smaller than 0?
CREATE TABLE "council_composition" (
  "party" text,
  "previous_council" real,
  "staying_councillors" real,
  "seats_up_for_election" real,
  "election_result" real,
  "new_council" real
);
SELECT AVG("new_council") FROM "council_composition" WHERE "election_result"<0;