What is the average number of drawn with a difference of 17 and 22 points?
CREATE TABLE "campeonato_paulista" (
  "position" real,
  "team" text,
  "points" real,
  "played" real,
  "drawn" real,
  "lost" real,
  "against" real,
  "difference" text
);
SELECT AVG("drawn") FROM "campeonato_paulista" WHERE "difference"='17' AND "points"=22;