What is the lowest average score where the evening gown score was 8.811?
CREATE TABLE "final_competition_score" (
  "country" text,
  "preliminary" real,
  "interview" real,
  "swimsuit" real,
  "evening_gown" real,
  "average" real
);
SELECT MIN("average") FROM "final_competition_score" WHERE "evening_gown"=8.811;