In 2004 Slovakia joined the European Union as a Member State, the Schengen area Member since 21 December 2007, and in 2009 the Eurozone, when the Euro was introduced to replace the Slovak Crown as the national currency. There are more than 5.4 million people in Slovakia. The country has 14 Members of European Parliament (MEPs). Slovakia has presided the EU between July and December 2016. Slovakia is a parliamentary democratic republic with a head of government - the prime minister - who holds the most executive power and a head of state - the president - who is the formal head of the executive, but with very limited powers. The country is subdivided into 8 regions, each named after its principal city. The country was in the centre of attention nad underwent huge political turbulences especially since February 2018 when the investigative journalist Ján Kuciak and his fiancée were murdered.