There is considerable movement toward the larger towns as population pressure on agricultural land increases. Some ethnic non-Tongans born on the islands migrate mainly to Fiji and New Zealand. Emigration by Tongan workers, both skilled and unskilled, has long been of concern to the government. In 1989 approximately 39,400 Tongans lived in the United States, Australia, and New Zealand. There are expatriate Tongan communities in Brisbane and Sydney (Australia), Auckland (New Zealand), San Francisco (United States), and on Hawaii. Persons wishing to reside in Tonga must obtain a government permit; permission is granted only to those taking up approved employment. Immigrant settlement is not encouraged because of the land shortage. The net migration rate in 1999 was -1.19 migrants per 1,000 population. There were an estimated 2,000 migrants in Tonga in the year 2000. The government views the migration levels as satisfactory.