CREATE TABLE table_63215 ("Island" TEXT, "Country" TEXT, "Population" TEXT, "Area km\\u00b2" TEXT, "Density  ( per km\\u00b2 ) " TEXT)

Which island has a density (per km ) of 1,368?
SELECT "Island" FROM table_63215 WHERE "Density (per km\u00b2)" = '1,368'
SELECT "Island" FROM "table_63215" WHERE "Density (per km\u00b2)" = '1,368'