Question: Superleague Greece is ranked 14th in the ranking system that was introduced in what year?

full_context: Document 1: France Football European Team of the Year: The "France Football" European Team of the Year (offic. fr. "Challenge Européen de Football"), also known as European Challenge Interclubs, was an association football award conferred by French sports magazine "France Football" with the sponsorship of German multinational corporation Adidas, and was held in Europe for the first time in 1968 based in clubs' performance in seasonal association and UEFA competitions.
Document 2: 2011–12 Superleague Greece: The 2011–12 Superleague Greece was the 53rd season of the highest football league of Greece and the sixth under the name Superleague. The season began in late August or early September 2011 and ended in May 2012 with the last matches of the European playoff round. Olympiacos are the defending champions, having won their 38th Greek championship in the 2010–11 season.
Document 3: Wales at the UEFA European Championship: This is a record of Wales' results at the UEFA European Championship. The UEFA European Championship, previously known at European Nations' Cup, is an international association football competition contested by the men's national teams of the members of "Union of European Football Associations" (UEFA), the administrative body for association football in Europe. The championship has been awarded every four years, since the first tournament in 1960.
Document 4: Superleague Greece Youth Leagues: The Superleague Greece Youth Leagues is a system of youth football leagues that are managed, organised and controlled by the Superleague. Youth Leagues are the organizational events involving the superleague clubs' infrastructure teams. It was established in 2002 as a single category, and in 2008 it split into two, until 2013 to three age levels. Previously known as the "Amateur Championship".
Document 5: UEFA coefficient: In European football, the UEFA coefficients are statistics used for ranking and seeding teams in club and international competitions. Introduced in 1979, the coefficients are calculated by UEFA, who administer football within Europe.
Document 6: 2015–16 Süper Lig: The 2015–16 Süper Lig (known as the "Spor Toto Süper Lig" for sponsorship reasons) is the 58th season of the Süper Lig, the highest tier football league of Turkey.
Document 7: Serbian SuperLiga: The Serbian SuperLiga (Serbian: Суперлига Србије, Superliga Srbije) is a Serbian professional league for football clubs. At the top of the Serbian football league system, it is the country's primary football competition. It is contested by 16 clubs, operating a system of promotion and relegation with the Serbian First League ("Prva liga Srbija", second Serbian football tier). The SuperLiga was formed during the summer of 2005 as the country's top football league competition in Serbia and Montenegro. Since summer 2006 after the secession of Montenegro from Serbia, the league only has had Serbian clubs.
Document 8: 2013–14 Superleague Greece: The 2013–14 Superleague Greece is the 78th season of the highest football league of Greece and the eighth under the name Superleague. The season began on August 17 and ended in May 2014. Olympiacos are the champions, having won their 41st Greek championship.
Document 9: UEFA Euro 2020: The 2020 UEFA European Football Championship, commonly referred to as UEFA Euro 2020 or simply Euro 2020, will be the 16th edition of the UEFA European Championship, the quadrennial international men's football championship of Europe organized by UEFA.
Document 10: Serie A: Serie A (] ), also called Serie A TIM due to sponsorship by TIM, is a professional league competition for football clubs located at the top of the Italian football league system and the winner is awarded the Coppa Campioni d'Italia. It has been operating for over eighty years since the 1929–30 season. It had been organized by Lega Calcio until 2010, when the Lega Serie A was created for the 2010–11 season. Serie A is regarded as one of the best football leagues in the world and it is often depicted as the most tactical national league. Serie A is the world's second-strongest national league according to IFFHS and has produced the highest number of European Cup finalists: Italian clubs have reached the final of the competition on a record 27 different occasions, winning the title 12 times. Serie A is ranked third among European leagues according to UEFA's league coefficient, behind La Liga, the Premier League and ahead of the Bundesliga and the Ligue 1, which is based on the performance of Italian clubs in the Champions League and the Europa League during the last five years. Serie A led the UEFA ranking from 1986 to 1988 and from 1990 to 1999.
Document 11: IFK Göteborg in European football: Idrottsföreningen Kamraterna Göteborg, commonly known as IFK Göteborg, is a Swedish professional football club based in Gothenburg. The club have participated in 32 editions of the club competitions governed by UEFA, the chief authority for football across Europe. These include 15 seasons in the European Cup and Champions League, 14 seasons in the UEFA Cup and Europa League, two seasons in the Cup Winners' Cup and one season in the Intertoto Cup. IFK Göteborg is the only club in the Nordic countries that has won a UEFA governed competition, as the club won the UEFA Cup in 1982 and 1987. Counting all of the 164 games the side have played in UEFA competitions since their first entry into the European Cup in the 1958–59 season, the team's record stands at 73 wins, 34 draws and 57 defeats.
Document 12: 2016–17 Ergotelis F.C. season: The 2016–17 season was Ergotelis' 87th season in existence and 1st season in the Gamma Ethniki, the third tier of the Greek football league system, after 14 years in which the club competed in professional competitions. Ergotelis also participated in the Gamma Ethniki Cup, a football competition cup in which only the clubs competing in one of the four groups of the Gamma Ethniki can participate. The season marked the beginning of a new era in the club's history, as the previous Football Club opened winding-up proceedings entering into liquidation, a process that allowed the parent sport club G.S. Ergotelis to form a new football department eligible to compete in the Gamma Ethniki under new leadership, free of the financial obligations of the previous administration. The club slogan for the season "Ksekiname!" (Greek: Ξεκινάμε! ) literally translates to "We begin!". The project was successful, as Ergotelis finished as Champions of Group 4, achieving instant promotion to the Football League, and professional divisions in general.
Document 13: 2012–13 Superleague Greece: The 2012–13 Superleague Greece was the 54th season of the highest football league of Greece and the seventh under the name Superleague. The season started on 25 August 2012 and ended on 2 June 2013 with the last matches of the European playoff round. Olympiacos were the defending champions, having won their 39th Greek championship in the 2011–12 season. They successfully defended their crown, finishing 15 points ahead of second-placed PAOK.
Document 14: Superleague Greece: The Superleague Greece (Greek: Ελληνική Σούπερ Λιγκ ) or Souroti Super League for sponsorship reasons, is the highest professional football league in Greece. It was formed on 16 July 2006 and replaced "Alpha Ethniki" at the top of the Greek football league system. The league consists of 16 teams and runs from August to May, with teams playing 30 games each. As of August 2017, Superleague Greece is ranked 14th in the UEFA ranking of leagues, based on performances in European competitions over the last five years.
Document 15: Campionato Sammarinese di Calcio: Campionato Sammarinese di Calcio (: Sammarinese Football Championship) is an amateur league competition for football clubs located at the top echelon of the Sammarinese football league system and has been operating since the 1985-1986 season. Currently, Campionato Sammarinese di Calcio is ranked at No.54/55 among European leagues according to UEFA's league coefficient, which is based on the performance of Sammarinese clubs in the Champions League and the Europa League.
ground_truth: 1979