Namibia's migrant labor force exceeds 100,000. Ovambo from northern Namibia have moved south since the 1920s to work in the diamond mines near the mouth of the Orange River, in the port of Walvis Bay, and in the cities and towns of the interior. Ovambo formerly migrated by the thousands to work in the gold mines of South Africa, but that traffic has diminished. Only 14,817 blacks of Namibian birth were resident in South Africa in 1991. Some Ovambo have gravitated from neighboring Angola into northern Namibia. The resurgence of war in Angola in mid-1998 drove thousands of refugees into Namibia. Between December 1998 and June 1999, the total number of refugees in Namibia increased from 2,700 to 4,300.
In 2000 there were 143,000 migrants residing in Namibia, including approximately 27,300 refugees. The net migration rate in that year was 0.6 per 1,000 population. The government views the immigration level as too high, but the emigration level as satisfactory.