 Complete the following phrase:  Rugby union participation in the U.S. has grown significantly in recent years, growing by 350 between 2004 and 2011. A 2010 survey by the National Sporting Goods Manufacturers Association ranked rugby union as the fastest-growing sport in the U.S. The sports profile in the U.S. has received a tremendous boost from the IOCs announcement in 2009 that rugby union in its seven-a-side variant would return to the Olympics in 2016. Since the Olympic announcement, rugby union events such as the Collegiate Rugby Championship, the USA Sevens, and the Rugby World Cup have been broadcast on network TV. The USA Sevens, held every year in February or March as part of the World Rugby Sevens Series, has regularly drawn more than 60,000 fans to Sam Boyd Stadium in Las Vegas, though the tournament will move to the Los Angeles area for at least its 2020 edition. The U.S. also hosts an event in the Womens Sevens Series. It had been held alongside the USA Sevens in the 201617 season, but was not held in 201718 when the 