As a member of the European Union, Estonia is considered a high-income economy by the World Bank. The GDP (PPP) per capita of the country, a good indicator of wealth, was in 2015 $28,781 according to the IMF, between that of Slovak Republic and Lithuania, but below that of other long-time EU members such as Italy or Spain. The country is ranked 8th in the 2015 Index of Economic Freedom, and the 4th freest economy in Europe. Because of its rapid growth, Estonia has often been described as a Baltic Tiger beside Lithuania and Latvia. Beginning 1 January 2011, Estonia adopted the euro and became the 17th eurozone member state.