CREATE TABLE table_name_41 (subregion VARCHAR(255), no_p VARCHAR(255), pop_area__1_km²_ VARCHAR(255))
Which Subregion has a No P. of 4, and a Pop/Area (1/km²) of 534?
    
SQL: SELECT subregion FROM table_name_41 WHERE no_p = 4 AND pop_area__1_km²_ = 534