According to residence permit data for 2011, more than 860,000 were Romanian, about 770,000 were Moroccan, approximately 390,000 were British, and 360,000 were Ecuadorian. Other sizeable foreign communities are Colombian, Bolivian, German, Italian, Bulgarian, and Chinese. There are more than 200,000 migrants from Sub-Saharan Africa living in Spain, principally Senegaleses and Nigerians. Since 2000, Spain has experienced high population growth as a result of immigration flows, despite a birth rate that is only half the replacement level. This sudden and ongoing inflow of immigrants, particularly those arriving illegally by sea, has caused noticeable social tension.