what is the average starts when the podiums is more than 0, stage wins is more than 39 and points is more than 456?
CREATE TABLE "constructors" (
  "constructor" text,
  "chassis" text,
  "starts" real,
  "finishes" real,
  "wins" real,
  "podiums" real,
  "stage_wins" real,
  "points" real
);
SELECT AVG("starts") FROM "constructors" WHERE "podiums">0 AND "stage_wins">39 AND "points">456;