What city was in the 3rd venue when Mexico City was in the 2nd? 
CREATE TABLE "list_of_fina_diving_world_series" (
  "year" real,
  "1st_venue" text,
  "2nd_venue" text,
  "3rd_venue" text,
  "4th_venue" text,
  "5th_venue" text
);
SELECT "3rd_venue" FROM "list_of_fina_diving_world_series" WHERE "2nd_venue"='Mexico City';