What is the sum of Average, when 2006 is "36/40", and when Played is greater than 126?
CREATE TABLE "relegation" (
  "team" text,
  "average" real,
  "points" real,
  "played" real,
  "2006" text,
  "2007" text,
  "2008" text
);
SELECT SUM("average") FROM "relegation" WHERE "2006"='36/40' AND "played">126;