In December 2019, there were 777,345 registered residents of foreign nationality and another 542,975 German citizens with a "migration background" ''(Migrationshintergrund, MH)'', meaning they or one of their parents immigrated to Germany after 1955. Foreign residents of Berlin originate from about 190 different countries. 48 percent of the residents under the age of 15 have migration background. Berlin in 2009 was estimated to have 100,000 to 250,000 unregistered inhabitants. Boroughs of Berlin with a significant number of migrants or foreign born population are Mitte, Neukölln and Friedrichshain-Kreuzberg.