Ireland has seen a recent rapid increase in their population. According to the New York Times the country grew by 8% or 322,645 in four years, split between new immigrants and births. Due to their birth rate and immigration, Ireland has the youngest population among the countries of the European Union. The new residents are often emigrants from Poland, Lithuania and Nigeria.

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Here are some interesting stats about the population of Ireland. http://www.statusireland.com/statistics/population-statistics-for-ireland/