What is the assumed office date of the prime minister ranked 22?
CREATE TABLE "rank_by_time_in_office" (
  "rank" real,
  "prime_minister" text,
  "party" text,
  "assumed_office" text,
  "left_office" text,
  "total_time_in_office" text
);
SELECT "assumed_office" FROM "rank_by_time_in_office" WHERE "rank"=22;