American football has the richest sports teams — 30 of the 50 most valuable sports teams in the world are in the National Football League, according to 2013 rankings. The NFL brings in about $9 billion US Dollars annually, with a team playing an average of a little more than 48 hours during a regular season. It is estimated that more than 100 million people watch an NFL game each Sunday during the season. The Dallas Cowboys are the most valuable NFL team, as of 2013, with an approximate value of about $1.85 billion USD, due in part to the renting out of the team's stadium for other sports events, such as the National Basketball Association All-Star Game, boxing matches and the National College Athletics Association basketball championship game.
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