The search for jobs in urban settings has caused a housing shortage in these areas. Several squatter settlements have developed, accounting for as much as half of annual shelter production in cities. It has been estimated that about 60% of the urban population resides in temporary shelters. In response, the government has been working with international programs, such as the World Bank, to create and improve urban housing. In 2001, the Swaziland National Housing Board provided for over 1,000 rental units and 500 units for ownership to low- and middle-income families.