What is the number for the interview in Illinois when the preliminary is less than 8.558?
CREATE TABLE "final_competition_score" (
  "country" text,
  "preliminary" real,
  "interview" real,
  "swimsuit" real,
  "evening_gown" real,
  "average" real
);
SELECT SUM("interview") FROM "final_competition_score" WHERE "country"='illinois' AND "preliminary"<8.558;