paragraph_text: The European Green Party was founded on 22 February 2004 at the Fourth Congress of the European Federation of Green Parties (EFGP) in Rome attended by over 1,000 delegates. Thirty-four Green parties from all over Europe have joined this new pan-European party. The Greens were the first to form a political party at European level. The other European political federations followed suit in the period 2004–06. For the Greens this was the culmination of a process which had started with the formation of a loose co-ordination 1979–93 and the EFGP 1993–2004.

paragraph_text: The European Coal and Steel Community (ECSC) was an organisation of 6 European countries set up after World War II to regulate their industrial production under a centralised authority. It was formally established in 1951 by the Treaty of Paris, signed by Belgium, France, West Germany, Italy, the Netherlands and Luxembourg. The ECSC was the first international organisation to be based on the principles of supranationalism, and started the process of formal integration which ultimately led to the European Union.

paragraph_text: Switzerland joined the Council of Europe in 1963. In 1979 areas from the canton of Bern attained independence from the Bernese, forming the new canton of Jura. On 18 April 1999 the Swiss population and the cantons voted in favour of a completely revised federal constitution.In 2002 Switzerland became a full member of the United Nations, leaving the Vatican City as the last widely recognised state without full UN membership. Switzerland is a founding member of the EFTA, but is not a member of the European Economic Area. An application for membership in the European Union was sent in May 1992, but not advanced since the EEA was rejected in December 1992 when Switzerland was the only country to launch a referendum on the EEA. There have since been several referendums on the EU issue; due to opposition from the citizens, the membership application has been withdrawn. Nonetheless, Swiss law is gradually being adjusted to conform with that of the EU, and the government has signed a number of bilateral agreements with the European Union. Switzerland, together with Liechtenstein, has been completely surrounded by the EU since Austria's entry in 1995. On 5 June 2005, Swiss voters agreed by a 55% majority to join the Schengen treaty, a result that was regarded by EU commentators as a sign of support by Switzerland, a country that is traditionally perceived as independent and reluctant to enter supranational bodies.

paragraph_text: In a referendum on 23 June 2016, 51.9% of the participating UK electorate voted to leave the EU, out of a turnout of 72.2%. On 29 March 2017, the UK government invoked Article 50 of the Treaty on the European Union. The UK is thus due to leave the EU on 29 March 2019.

paragraph_text: Until recently, in the absence of prior agreement on a clear and precise definition, the concept was thought to mean (as a shorthand) 'a division of sovereignty between two levels of government'. New research, however, argues that this cannot be correct, as dividing sovereignty - when this concept is properly understood in its core meaning of the final and absolute source of political authority in a political community - is not possible. The descent of the United States into Civil War in the mid-nineteenth century, over disputes about unallocated competences concerning slavery and ultimately the right of secession, showed this. One or other level of government could be sovereign to decide such matters, but not both simultaneously. Therefore, it is now suggested that federalism is more appropriately conceived as 'a division of the powers flowing from sovereignty between two levels of government'. What differentiates the concept from other multi-level political forms is the characteristic of equality of standing between the two levels of government established. This clarified definition opens the way to identifying two distinct federal forms, where before only one was known, based upon whether sovereignty resides in the whole (in one people) or in the parts (in many peoples): the federal state (or federation) and the federal union of states (or federal union), respectively. Leading examples of the federal state include the United States, Germany, Canada, Switzerland, Australia and India. The leading example of the federal union of states is the European Union.

paragraph_text: The GDP of Thuringia is below the national average, in line with the other former East German Lands. Until 2004, Thuringia was one of the weakest regions within the European Union. The accession of several new countries, the crisis in southern Europe and the sustained economic growth in Germany since 2005 has brought the Thuringian GDP close to the EU average since then. The high economic subsidies granted by the federal government and the EU after 1990 are being reduced gradually and will end around 2020.

paragraph_text: The 1960s and 1970s saw an acceleration in the decolonisation of Africa and the Caribbean. Over 20 countries gained independence from Britain as part of a planned transition to self-government. In 1965, however, the Rhodesian Prime Minister, Ian Smith, in opposition to moves toward majority rule, declared unilateral independence from Britain while still expressing "loyalty and devotion" to Elizabeth. Although the Queen dismissed him in a formal declaration, and the international community applied sanctions against Rhodesia, his regime survived for over a decade. As Britain's ties to its former empire weakened, the British government sought entry to the European Community, a goal it achieved in 1973.

paragraph_text: Switzerland voted against membership in the European Economic Area in a referendum in December 1992 and has since maintained and developed its relationships with the European Union (EU) and European countries through bilateral agreements. In March 2001, the Swiss people refused in a popular vote to start accession negotiations with the EU. In recent years, the Swiss have brought their economic practices largely into conformity with those of the EU in many ways, in an effort to enhance their international competitiveness. The economy grew at 3% in 2010, 1.9% in 2011, and 1% in 2012. Full EU membership is a long-term objective of some in the Swiss government, but there is considerable popular sentiment against this supported by the conservative SVP party. The western French-speaking areas and the urban regions of the rest of the country tend to be more pro-EU, however with far from any significant share of the population.

paragraph_text: Italy became a major industrialized country again, due to its post-war economic miracle. The European Union (EU) involved the division of powers, with taxation, health and education handled by the nation states, while the EU had charge of market rules, competition, legal standards and environmentalism. The Soviet economic and political system collapsed, leading to the end of communism in the satellite countries in 1989, and the dissolution of the Soviet Union itself in 1991. As a consequence, Europe's integration deepened, the continent became depolarised, and the European Union expanded to subsequently include many of the formerly communist European countries – Romania and Bulgaria (2007) and Croatia (2013).

paragraph_text: United Kingdom European Union membership referendum, 2016 Northern Ireland Choice Votes% Remain a member of the European Union 440,707 55.78% Leave the European Union 349,442 44.22% Valid votes 790,149 99.95% Invalid or blank votes 374 0.05% Total votes 790,523 100.00% Registered voters and turnout 1,260,955 62.69% Source: Electoral Commission

paragraph_text: Reciprocal arrangements allow British and Irish citizens to full voting rights in the two states. Exceptions to this are presidential elections and constitutional referendums in the Republic of Ireland, for which there is no comparable franchise in the other states. In the United Kingdom, these pre-date European Union law, and in both jurisdictions go further than that required by European Union law. Other EU nationals may only vote in local and European Parliament elections while resident in either the UK or Ireland. In 2008, a UK Ministry of Justice report investigating how to strengthen the British sense of citizenship proposed to end this arrangement arguing that, "the right to vote is one of the hallmarks of the political status of citizens; it is not a means of expressing closeness between countries."

paragraph_text: "Soviet Strike" is set after the disintegration of the Soviet Union, and takes place in a fictionalised Russia, Eastern Europe and around the Caspian Sea. The player pilots an Apache helicopter and battles with the forces of Shadowman, a renegade ex-communist figure. Like its predecessors, the game features shooting action mixed with strategic management of fuel and ammunition, but has more authentic 3D graphics, as well as a modified overhead - as opposed to isometric - perspective. The game also features a more realistic enemy artificial intelligence and environment. Critics received the game positively, praising the graphics and full motion video, while commentary on the gameplay and difficulty was more mixed.

paragraph_text: Turkey's application to accede to the European Economic Community, the predecessor of the European Union (EU), was made on 14 April 1987. After the ten founding members, Turkey was one of the first countries to become a member of the Council of Europe in 1949. The country has also been an associate member of the Western European Union from 1992 to its end in 2011. Turkey signed a Customs Union agreement with the EU in 1995 and was officially recognised as a candidate for full membership on 12 December 1999, at the Helsinki summit of the European Council.

paragraph_text: In 1986, Portugal joined the European Economic Community (EEC) that later became the European Union (EU). In the following years Portugal's economy progressed considerably as a result of EEC/EU structural and cohesion funds and Portuguese companies' easier access to foreign markets.

paragraph_text: Greece is a democratic and developed country with an advanced high-income economy, a high quality of life and a very high standard of living. A founding member of the United Nations, Greece was the tenth member to join the European Communities (precursor to the European Union) and has been part of the Eurozone since 2001. It is also a member of numerous other international institutions, including the Council of Europe, NATO,[a] OECD, OIF, OSCE and the WTO. Greece, which is one of the world's largest shipping powers, middle powers and top tourist destinations, has the largest economy in the Balkans, where it is an important regional investor.

paragraph_text: The Battle of Apache Pass was fought in 1862 at Apache Pass, Arizona, in the United States, between Apache warriors and the Union volunteers of the California Column as it marched from California to capture Confederate Arizona and to reinforce New Mexico's Union army. It was one of the largest battles between the Americans and the Chiricahua during the Apache Wars.

paragraph_text: The Army Air Corps (AAC) is a component of the British Army, first formed in 1942 during the Second World War by grouping the various airborne units of the British Army (which are no longer part of the AAC). Today, there are eight regiments (7 Regular Army and 1 Reserve) of the AAC as well as four Independent Flights and two Independent Squadrons deployed in support of British Army operations across the world. They are located in Britain, Brunei, Canada, and Germany. Some AAC squadrons provide the offensive and air assault elements of 16 Air Assault Brigade through Joint Helicopter Command.

paragraph_text: The 2007 enlargement of the European Union saw Bulgaria and Romania join the European Union (EU) on 1 January 2007. Together with the 2004 enlargement of the European Union, it is considered part of the fifth wave of enlargement of the European Union.

paragraph_text: The 2013 enlargement of the European Union saw Croatia join the European Union as its 28th member state on 1 July 2013.

paragraph_text: In recent years a number of well-known tourism-related organizations have placed Greek destinations in the top of their lists. In 2009 Lonely Planet ranked Thessaloniki, the country's second-largest city, the world's fifth best "Ultimate Party Town", alongside cities such as Montreal and Dubai, while in 2011 the island of Santorini was voted as the best island in the world by Travel + Leisure. The neighbouring island of Mykonos was ranked as the 5th best island Europe. Thessaloniki was the European Youth Capital in 2014.

Question: When did the country where Apache helicopters are based in the nation that recently voted to leave a federal union join the European Community?
Answer: 1973