Some of the shortfall in population may have been made good by the inward migration of families groups of so-called "Anguru", Lomwe speaking migrants from the parts of Mozambique east of the Shire Highlands estates, who became estate tenants. They began to arrive from 1899, and the 1921 census counted 108,204 “Anguru”. Neither the 1901 nor the 1911 censuses recorded tribal affiliation, but the very substantial population increases in districts adjacent to Mozambique, especially Blantyre and Zomba districts, whose recorded populations more than doubled in this decade, suggest substantial immigration. In this period, relatively few Africans left the protectorate as migrant workers, but outward labour migration became more common later.