Question: Olakunle "Kay" Banjo (born December 3, 1992) is an American soccer player who plays for the Pittsburgh Riverhounds in the United Soccer League (USL), formerly known as USL Pro, is a professional men's soccer league in the United States and Canada that began its inaugural season in what year?

full_context: Document 1: Landon Donovan: Landon Timothy Donovan (born March 4, 1982) is an American former professional soccer player who played as a forward and attacking midfielder. He holds numerous individual records in Major League Soccer (MLS) and for the United States national team and is often regarded as the greatest American men's soccer player of all-time.
Document 2: Premier Development League: The Premier Development League (commonly known as the PDL) is a development league sponsored by United Soccer Leagues in the United States and Canada, forming part of the United States soccer league system. The league has 72 teams competing in four conferences, split into ten regional divisions. Unofficially, it is considered to be the fourth tier of competition, behind Major League Soccer, the North American Soccer League and the United Soccer League. With USL Pro re-branding as the United Soccer League in February 2015, the PDL dropped the "USL" descriptor from their name, simply operating as the "Premier Development League". PDL is headquartered in Tampa.
Document 3: National Women's Soccer League: The National Women's Soccer League (NWSL) is a professional women's soccer league, run by the United States Soccer Federation. At the top of the United States league system, it represents the sport's highest level in the United States. The NWSL was established in 2012 as a successor to Women's Professional Soccer (2007–2012) which was the successor to Women's United Soccer Association (2001–2003). The league began play in 2013 with eight teams; four of which were former members of Women's Professional Soccer. With the addition of two expansion teams in Houston and Orlando since the league's founding, it now has 10 teams based throughout the United States.
Document 4: 2010 Miami FC season: The 2010 Miami FC season was the fifth season of the club. Previously, they fielded a team in the USL First Division. Along with other clubs, Miami FC broke away from the previous league to form the new North American Soccer League. Nonetheless, the club fielded a team in the NASL Conference of the USSF Division 2 Professional League, the second tier of the American Soccer Pyramid at the time. (The USSF D2 was a temporary professional soccer league created by the United States Soccer Federation (USSF) in 2010 to last just one season. It was a compromise between the debating United Soccer Leagues (USL) and the North American Soccer League (NASL) while the USSF determined which league would eventually receive second or third division status). This year the team finished fourth in the NASL Conference Standings and ninth in the playoff standings, missing the post season. This was the last year of the team as the new NASL was launched the following year. The club connected with the original Fort Lauderdale Strikers club and launched a new team and franchise in the NASL under the Strikers' name starting in the 2011 season.
Document 5: North American Soccer League: The North American Soccer League (NASL) is a professional men's soccer league with eight teams: six in the United States, one in Canada and one in Puerto Rico. It is sanctioned by the United States Soccer Federation (U.S. Soccer) as a Division II league in the United States soccer league system, under Major League Soccer (MLS) and alongside United Soccer League (formerly USL Pro). It is headquartered in New York City.
Document 6: Major League Soccer attendance: Major League Soccer is the premier professional soccer league in the United States and Canada. Competition began in 1996, the 2016 season saw an average 21,692 spectators between the 20 teams, the highest average attendance in league history. MLS has the third-highest average attendance among all professional sports leagues with teams in the United States, ranking behind the National Football League and Major League Baseball but ahead of the National Basketball Association and National Hockey League. Among all North American professional sports leagues, MLS ranks fifth in average attendance per game behind the NFL and MLB as well as Liga MX and the Canadian Football League.
Document 7: Moise Kean: Moise Bioty Kean ( [kɛn] ; born 28 February 2000) is an Italian professional footballer who plays as a forward for Hellas Verona, on loan from Juventus. In November 2016, he became the first player born in the 2000s to make an appearance in one of Europe's five major leagues, as well as in the UEFA Champions League. Later in May 2017, he became the first player born in the 2000s to score a goal in one of Europe's five major leagues.
Document 8: Clarence Kay: Clarence Hubert Kay (born July 30, 1961 in Seneca, South Carolina) is a former professional American football player. A 6'2", 237-lb. tight end from the University of Georgia, Kay was selected by the Denver Broncos in the 7th round of the 1984 NFL Draft. Kay played in 9 NFL seasons from 1984–1992, all with the Broncos.
Document 9: Kay Banjo: Olakunle "Kay" Banjo (born December 3, 1992) is an American soccer player who plays for the Pittsburgh Riverhounds in the USL.
Document 10: Michael Kay (footballer): Michael Joseph Kay (born 9 December 1989 in Consett, England) is an English former footballer. He usually played in the right back position, but could also play as a central defender and has been known to fill in as a left back on occasion. He is a former England Under-17 international. He is no relation to former Sunderland defender John Kay.
Document 11: Orlando City SC (2010–14): Orlando City SC were an American professional soccer team based in Orlando, Florida, United States that was the precursor to Orlando City SC. The team played in USL Pro, the third tier of the American soccer pyramid from 2010 to 2014, until discontinuing in favor of Orlando's Major League Soccer (MLS) expansion franchise in 2015 which is owned by the same principals.
Document 12: Asamoah Gyan: Asamoah Gyan ( , , born 22 November 1985 in Accra) is a Ghanaian professional footballer who plays as a striker for Kayserispor and captains the Ghanaian national team.
Document 13: National Premier Soccer League: The National Premier Soccer League (NPSL) is an American soccer league commonly recognized as being a fourth tier league although it has been given no official designation by US Soccer. Although the league is officially affiliated to the United States Adult Soccer Association (USASA) and qualifies for the U.S. Open Cup through USASA channels, the league is generally considered to be at the fourth tier of competition in the United States soccer pyramid, behind Major League Soccer (MLS), the North American Soccer League (NASL), and the United Soccer League (USL), and roughly equal with the Premier Development League (PDL). It is the successor of the Men's Premier Soccer League, a regional league originally based out of the Western United States, which has now expanded nationwide to encompass teams from 29 states. The league's motto is "A National League with a Regional Focus". Some of the clubs are former USL clubs.
Document 14: Matthew Olosunde: Matthew Olosunde (born March 7, 1998) is an American soccer player who plays for Manchester United U23s as a right-back.
Document 15: United Soccer League: The United Soccer League (USL), formerly known as USL Pro, is a professional men's soccer league in the United States and Canada that began its inaugural season in 2011. USL is sanctioned as a Division II Professional League by the United States Soccer Federation (U.S. Soccer), placing it under Major League Soccer (Division I) in the hierarchy. The USL is headquartered in Tampa.
ground_truth: 2011