What is the League Goals when the FA Cup Goals are 0, position is mf, League Cup Apps of 0, and name is Ben Thornley?
CREATE TABLE "appearances_and_goals" (
  "name" text,
  "position" text,
  "league_apps" text,
  "league_goals" real,
  "fa_cup_apps" text,
  "fa_cup_goals" real,
  "league_cup_apps" text,
  "league_cup_goals" real,
  "total_apps" text,
  "total_goals" real
);
SELECT AVG("league_goals") FROM "appearances_and_goals" WHERE "fa_cup_goals"=0 AND "position"='mf' AND "league_cup_apps"='0' AND "name"='ben thornley';