At the end of 2008, the Italian population surpassed 60 million.[25] Italy currently has the fourth-largest population in the European Union and the 23rd-largest population worldwide. Italy's population density, at 199.2 persons per square kilometre, is the fifth highest in the European Union. The highest density is in Northern Italy, as that one-third of the country contains almost half of the total population. After World War II, Italy enjoyed a prolonged economic boom which caused a major rural exodus to the cities, and at the same time transormed the nation from a massive emigration country to a net immigrant-receiving country. High fertility persisted until the 1970s, when it plunged below the replacement rates, so that as of 2008, one in five Italians was over 65 years old. Despite this, thanks mainly to the massive immigration of the last two decades, in the 2000s Italy saw a crude birth rates growth (especially in the northern regions) for the first time in many years.The total fertility rate also significantly grew in the past few years, thanks both to rising births in foreign born and Italian women, as it climbed to 1.41 children per woman in 2008 compared to 2005 when it sat at 1.32.