The local natives who speak Quechua adopted that language either after they were conquered by the Inca Empire (that reached Tucumán) or by the teachings of the Spanish religious missionaries who came from Peru to today's Santiago del Estero Province; the language is quickly losing importance. The Survey on Indigenous Populations, published by the National Institute for Statistics and Census, gives a total of 600,329 people who see themselves as descending from or belonging to an indigenous people, representing 1.5% of Argentina's population.