Cities such as Hamburg and Berlin, which were formerly centres of occupation forces following World War II and more recent immigration, have substantial Afro-German communities, with a relatively high percentage of ethnically mixed and multiracial families.  With modern trade and migration, communities such as Frankfurt, Munich, and Cologne have an increasing number of Afro-Germans. As of 2013[update], there were approximately 817,000 Afro-Germans in a country with a population of 82,000,000 people. This number is difficult to estimate because the German census does not use race as a category, following the genocide committed during World War II under the "German racial ideology". Up to 70,000 (2% of the population) people of Afro-German origin live in Berlin.