What is the greatest B score when the A score was less than 6.5?
CREATE TABLE "floor_event_final_qualifiers" (
  "position" text,
  "gymnast" text,
  "a_score" real,
  "b_score" real,
  "total" real
);
SELECT MAX("b_score") FROM "floor_event_final_qualifiers" WHERE "a_score"<6.5;