Question: Which division did Oklahoma City Thunder win in 2015-16, their first season under current head coach Billy Donovan?

full_context: Document 1: List of Oklahoma City Thunder seasons: The Oklahoma City Thunder are a professional basketball team based in Oklahoma City, Oklahoma. They play in the National Basketball Association (NBA) and are a member of the NBA Western Conference's Northwest Division. The Thunder were founded in 1967 as the Seattle SuperSonics as one of two franchises that joined the NBA in the 1967–68 season. The SuperSonics moved to Oklahoma City after the 2007–08 season. The move from Seattle to Oklahoma City marks only the second time that a current franchise won a title in one city and moved some time afterwards to another city (the 2nd are the Atlanta Hawks who left St. Louis after winning the 1958 title there).
Document 2: Billy Donovan: William John Donovan Jr. (born May 30, 1965) is an American professional basketball coach who is currently the head coach for the Oklahoma City Thunder of the National Basketball Association (NBA). He previously spent 19 seasons at the University of Florida, where his Florida Gators teams won back-to-back NCAA championships in 2006 and 2007. Donovan has more wins than any other coach in the history of the Florida basketball program, and he coached the Gators to more NCAA tournament appearances, NCAA tournament wins, and Southeastern Conference (SEC) championships than all other Florida coaches combined.
Document 3: 2014–15 Oklahoma City Thunder season: The 2014–15 Oklahoma City Thunder season is the 7th season of the franchise in Oklahoma City and the 48th in the National Basketball Association (NBA).
Document 4: 2012–13 Oklahoma City Thunder season: The 2012–13 Oklahoma City Thunder season was the 5th season of the franchise in Oklahoma City and the 47th in the National Basketball Association (NBA). After their trip to the NBA Finals, despite losing the Finals to the Miami Heat in five games, the Thunder improved on last season's output, winning 60 games, earning them the top seed in the Western Conference. The first round pitted the Thunder against the eight-seeded Houston Rockets, led by James Harden, a former Thunder player. Despite a season-ending injury to Russell Westbrook in game 2, the Thunder still managed to breeze past the Rockets in six games, to advance to the next round, where they faced the Memphis Grizzlies. The absence of Westbrook, however, affected the Thunder and they would end up losing to the Grizzlies in five games.
Document 5: Bill Self: Billy Eugene Self Jr. (born December 27, 1962) is an American men's college basketball coach at the University of Kansas. During his 14 seasons as head coach, he has led the Jayhawks to at least a share of 13 straight Big 12 regular season championships (2005–2017), 2 NCAA Final Four appearances (2008, 2012), and the 2008 NCAA championship. On March 31, 2017, it was announced that Self had been elected into the Naismith Memorial Basketball Hall of Fame. The official induction will be later in 2017.
Document 6: 2017–18 Oklahoma City Thunder season: The 2017–18 Oklahoma City Thunder season will be the 10th season of the franchise in Oklahoma City and the 52nd in the National Basketball Association (NBA). This season was headlined by the acquisitions of All-Stars Paul George and Carmelo Anthony in trades with the Indiana Pacers and New York Knicks respectively. It also highlighted one of their first ever (original) All-Stars in Russell Westbrook signing a five-year extension worth $205 million.
Document 7: 2014–15 Florida Gators men's basketball team: The 2014–15 Florida Gators men's basketball team represented the University of Florida in the sport of basketball during the 2014–15 NCAA Division I men's basketball season. The Gators competed in the Southeastern Conference (SEC). They were led by nineteen-year head coach Billy Donovan, and played their home games in the O'Connell Center on the university's Gainesville, Florida campus. They finished the season 16–17, 8–10 in SEC play to finish in a tie for eighth place. They advanced to the quarterfinals of the SEC Tournament where they lost to Kentucky.
Document 8: William Donavan III: William Connor Donovan III is an American professional basketball coach for the Austin Spurs. He is the son of Billy Donovan the head coach for the Oklahoma City Thunder of the National Basketball Association (NBA).
Document 9: List of Oklahoma City Thunder head coaches: The Oklahoma City Thunder is an American professional basketball franchise based in Oklahoma City, Oklahoma. It plays in the Northwest Division of the Western Conference in the National Basketball Association (NBA). It was known as the Seattle SuperSonics from 1967 to 2008. The team plays its home games at the Chesapeake Energy Arena. As of October 2008, the Thunder is currently owned by Professional Basketball Club LLC and coached by Billy Donovan, with Sam Presti as its general manager. The team was formed in 1967. After spending 41 seasons in Seattle, Washington, the SuperSonics moved to Oklahoma City. Owner Clay Bennett, who purchased the team in 2006, sought to get public funding for a new arena in Seattle, or a major renovation of the KeyArena in 2007. After failing to do so, he decided to move the team to Oklahoma City. Seattle sued Bennett's group to enforce the lease that required the team to stay until 2010. The two sides reached a $45 million settlement to pay off the team's lease with KeyArena in July 2008.
Document 10: 2006–07 Florida Gators men's basketball team: The 2006–07 Florida Gators men's basketball team represented the University of Florida in the sport of basketball during the 2006–07 college basketball season. The Gators competed in Division I of the National Collegiate Athletic Association (NCAA) and the Eastern Division of the Southeastern Conference (SEC). They were led by head coach Billy Donovan, and played their home games in the O'Connell Center on the university's Gainesville, Florida campus.
Document 11: 2010–11 Florida Gators men's basketball team: The 2010–11 Florida Gators men's basketball team represented the University of Florida in the sport of basketball during the 2010–11 college basketball season. The Gators competed in Division I of the National Collegiate Athletic Association (NCAA) and the Eastern Division of the Southeastern Conference (SEC). They were led by head coach Billy Donovan, and played their home games in the O'Connell Center on the university's Gainesville, Florida campus.
Document 12: 2016–17 Oklahoma City Thunder season: The 2016–17 Oklahoma City Thunder season was the 9th season of the franchise in Oklahoma City and the 51st in the National Basketball Association (NBA). On the 4th of July, Kevin Durant announced he would leave the Thunder and sign with the Golden State Warriors. On the April 9, Russell Westbrook broke the record of Oscar Robertson of most triple-doubles in a season with 42. Westbrook would go on to be named the League's MVP in June.
Document 13: 2015–16 Oklahoma City Thunder season: The 2015–16 Oklahoma City Thunder season was the 8th season of the franchise in Oklahoma City and the 50th in the National Basketball Association (NBA), and the first under head coach Billy Donovan. After coming just short of making the playoffs the previous season, the Thunder won the Northwest Division and clinched the third seed in the Western Conference. The team reached the Western Conference Finals for the fourth time in a span of six seasons, but was eliminated by the Golden State Warriors in seven games after leading the series 3-1. After the season Kevin Durant left the team in free agency for the Warriors.
Document 14: 2011–12 Oklahoma City Thunder season: The 2011–12 Oklahoma City Thunder season was the 4th season of the franchise's existence in Oklahoma City as a member of the National Basketball Association (NBA). The Thunder continued to build on recent success in previous years by making the NBA Playoffs, defeating and sweeping the defending NBA champions, the Dallas Mavericks in the First Round, the Los Angeles Lakers in the Semifinals, and finally, the San Antonio Spurs in the Western Conference Finals to advance to the NBA Finals. Despite winning Game 1 in the NBA Finals, the Thunder would then go on to lose the next four games and the NBA Finals against the Miami Heat.
Document 15: 2000–01 Florida Gators men's basketball team: The 2000–01 Florida Gators men's basketball team represented the University of Florida in the sport of basketball during the 2000–01 college basketball season. The Gators competed in Division I of the National Collegiate Athletic Association (NCAA) and the Eastern Division of the Southeastern Conference (SEC). They were led by head coach Billy Donovan, and played their home games in the O'Connell Center on the university's Gainesville, Florida campus.
ground_truth: Northwest Division