How many staying councillors were there when the election result was larger than 0, the new council less than 27 and the party conservatives?
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("staying_councillors") FROM "council_composition" WHERE "election_result">0 AND "party"='conservatives' AND "new_council"<27;