The Cavaliers won the Eastern Conference (NBA) in 2006-07 NBA season, 2014-15 NBA season, 2015-16 NBA season, 2016-17 NBA season and 2017-18 NBA season but were defeated in the 2007 NBA Finals by the San Antonio Spurs and 2015 NBA Finals the Golden State Warriors, respectively. The Cavs won the Conference again in 2016 NBA Finals and won their first NBA Championship coming back from a 3-1 deficit, finally defeating the Golden State Warriors. Afterwards, an estimated 1.3 million people attended a parade held in the Cavs honor on June 22, 2016. This was the first time the city had planned for a championship parade in 50 years. Basketball, the Cleveland Rosenblums dominated the original American Basketball League (1925-55) winning three of the first five championships (1926, 1929, 1930), and the Cleveland Pipers, owned by George Steinbrenner, won the American Basketball League (1961-63) championship in 1962.
Question: How many years apart were the first and last championships won by the Cleveland Rosenblums?
Answer: 4