What is the average Percentage when there are more than 0 wins, Points Against is more than 481, Losses of 8, and a Points For larger than 826?
CREATE TABLE "standings" (
  "club" text,
  "wins" real,
  "losses" real,
  "points_for" real,
  "points_against" real,
  "percentage" real,
  "points" real
);
SELECT AVG("percentage") FROM "standings" WHERE "wins">0 AND "points_against">481 AND "losses"=8 AND "points_for">826;