Approximately 67% of Bolivians live in urban areas, among the lowest proportion in South America. Nevertheless, the rate of urbanization is growing steadily, at around 2.5% annually. According to the 2012 census, there are total of 3,158,691 households in Bolivia – an increase of 887,960 from 2001. In 2009, 75.4% of homes were classified as a house, hut, or Pahuichi; 3.3% were apartments; 21.1% were rental residences; and 0.1% were mobile homes. Most of the country's largest cities are located in the highlands of the west and central regions.