CREATE TABLE table_204_554 (id DECIMAL, "rank" DECIMAL, "name" TEXT, "nation" TEXT, "time" TEXT, "speed" DECIMAL, "note" TEXT)

which country rank last ?
SELECT "nation" FROM table_204_554 ORDER BY "rank" DESC LIMIT 1
SELECT "nation" FROM "table_204_554" ORDER BY "rank" DESC NULLS LAST LIMIT 1