The National Collegiate Athletic Association (NCAA)[a] is a non-profit association which regulates athletes of 1,281 institutions, conferences, organizations, and individuals. It also organizes the athletic programs of many colleges and universities in the United States and Canada, and helps more than 450,000 college student-athletes who compete annually in college sports. The organization is headquartered in Indianapolis, Indiana. In 2014, the NCAA generated almost a billion dollars in revenue. 80 to 90% of this revenue was due to the Mens Division I Basketball Tournament. This revenue is then distributed back into various organizations and institutions across the United States. In August 1973, the current three-division setup of Division I, Division II, and Division III was adopted by the NCAA membership in a special convention. Under NCAA rules, Division I and Division II schools can offer scholarships to athletes for playing a sport. Division III schools may not offer any athletic scholarships. Generally, larger schools compete in Division I and smaller schools in II and III. Division I football was further divided into I-A and I-AA in 1978. Subsequently, the term "Division I-AAA" was briefly added to delineate Division I schools which do not field a football program at all, but that term is no longer officially used by the NCAA. In 2006, Divisions I-A and I-AA were respectively renamed the Football Bowl Subdivision (FBS) and Football Championship Subdivision (FCS). Inter-collegiate sports began in the US in 1852 when crews from Harvard University and Yale University met in a challenge race in the sport of rowing. As rowing remained the preeminent sport in the country into the late-1800s, many of the initial debates about collegiate athletic eligibility and purpose were settled through organizations like the Rowing Association of American Colleges and the Intercollegiate Rowing Association. As other sports emerged, notably football and basketball, many of these same concepts and standards were adopted. Football, in particular, began to emerge as a marquee sport, but the rules of the game itself were in constant flux and often had to be adapted for each contest.