Havana agglomeration grew rapidly during the first half of the 20th century reaching 1 million inhabitants in the 1943 census. The con-urbanization expanded over the Havana municipality borders into neighbor municipalities of Marianao, Regla and Guanabacoa. Starting from the 1980s, the city's population is growing slowly as a result of balanced development policies, low birth rate, its relatively high rate of emigration abroad, and controlled domestic migration. Because of the city and country's low birth rate and high life expectancy, its age structure is similar to a developed country, with Havana having an even higher proportion of elderly than the country as a whole.