Before independence, the size of the European population waxed and waned with the fortunes of the mining industry. During the political upheavals of the mid-1960s, many Europeans in the mining industries left Zambia. As of 1999, there were nearly 200,000 refugees in Zambia. Most were from Angola; the rest were from the DROC, Rwanda, Burundi, and other African countries. The net migration rate in 2000 was -1.4 migrants per 1,000 population. There were 377,000 migrants living in Zambia that year, including refugees. The government views the migration levels as satisfactory.