CREATE TABLE table_203_222 (id DECIMAL, "category" TEXT, "#" DECIMAL, "name" TEXT, "hanzi" TEXT, "hanyu pinyin" TEXT, "population  ( 2010 census ) " DECIMAL, "area  ( km2 ) " DECIMAL, "density  ( /km2 ) " DECIMAL)

which area is the least dense ?
SELECT "name" FROM table_203_222 ORDER BY "density (/km2)" LIMIT 1
SELECT "name" FROM "table_203_222" ORDER BY "density (/km2)" NULLS FIRST LIMIT 1