CREATE TABLE table_18805 ("Rank by average" FLOAT, "Competition finish" FLOAT, "Couple" CLOB, "Total" FLOAT, "Number of dances" FLOAT, "Average" CLOB)

what is the highest number where people got done at 31.1
SELECT MAX("Competition finish") FROM table_18805 WHERE "Average" = '31.1'
SELECT MAX("Competition finish") FROM "table_18805" WHERE "Average" = '31.1'