CREATE TABLE table_204_710 (id DECIMAL, "model" TEXT, "origin" TEXT, "type" TEXT, "versions" TEXT, "in service" TEXT, "notes" TEXT)

what country has the last listed aircraft ?
SELECT "origin" FROM table_204_710 ORDER BY id DESC LIMIT 1
SELECT "origin" FROM "table_204_710" ORDER BY "id" DESC NULLS LAST LIMIT 1