The dominant physical feature of Chile is the Cordillera de los Andes, which is born in the Colombian-Venezuelan guajira and travels the country from north to south, to Tierra del Fuego. The topography is a decisive geographic element in the population and in the economy. Chile is a mountain country; the plains represent only twenty percent of the area. This feature strongly influences the distribution of the population, which is concentrated on the coastal plains and intermediate depressions, and its concentration decays with the distance from these areas. This abrupt landscapes have a great influence in the SWOT of the country. For example, the arid, cold (with perennial snow), or high zones with low level of oxygen, are weakness because their inhospitable conditions for settlements, agriculture, and others, but many of their geologic formations represent an economic opportunity due to the presence of ores, energetic resources, water, etc. Also, many areas with remarkable slope represent a threat because of the possibility of landslides or floods during raining seasons or due to ice melts. Also, the mountainous topography increases the actual distance between different sites and human settlements. Only in the desert north, where precipitation creates a pasture belt above 2,500 m above sea level, there are human populations in height. In the rest of the country, human settlements descend: in Santiago to 1,400 m, in Curicó to 1,000 m and in Llanquihue to 700 m. To the south, populations are only established in the lower parts. Chile is divided into the following regions: I Tarapacá, II Antofagasta, III Atacama, IV Coquimbo, V Valparaiso, VI O'Higgins, VII Maule, VIII Biobío, IX Araucanía, X Los Lagos, XI Aysén, XII Magellan and Antarctica, Región Metropolitana, XIV Los Ríos, and XV Arica and Parinacota. It can be divided longitudinally (vertically) into three morphological regions: the majestic Andes mountain range to the east, the Cordillera de la Costa to the west, and the plateau area and the Longitudinal valley or Intermediate depression, located between both chains. Latitudinally (horizontally), three major geographic and climatological regions are distinguished: northern (arid), central (Mediterranean) and southern (temperate). The inhabitants of Chile (according to results of the 2012 census) total about 16,000,000 people, and it is very homogeneous. Spanish is the official language of Chile, practically spoken by all the population. The use of Aboriginal languages is limited. It is currently only possible to find four surviving Amerindian languages; these are Aymara, Quechua, Mapuche and Kawésqar, and also one non-Amerindian in Easter Island (rapa nui). In addition, six dialects have become extinct, chango, atacameño, diaguita, selk'nam, yagán and chono, some practically without leaving traces. According to the 2002 census, 4.58% of the country's population, or 692,192 people aged 14 years or older, is indigenous. Between the eight ethnic groups recognized in the country, 87.31% are Mapuche, 7.01% Aymara, 3.04% Atacameño, 0.89% Quechua, 0.67% Rapanui, 0.46% Kolla, % Kawésqar and 0.24% yagán. There is freedom of worship, and Catholics constitute approximately 81% of the Chilean population, although officially the Church separated from the state in 1925. Most of the rest of the population professes the Protestant Pentecostal or Evangelical religion. Indigenous people who practice their traditional religions are a tiny minority.