what is the highest number where people got done at 31.1
CREATE TABLE "average_chart" (
  "rank_by_average" real,
  "competition_finish" real,
  "couple" text,
  "total" real,
  "number_of_dances" real,
  "average" text
);
SELECT MAX("competition_finish") FROM "average_chart" WHERE "average"='31.1';