The report (available for purchase, here) states there has been a 10 percent growth in the number of "frequent" tennis players (those who play at least 21 times a year), up to 5.31 million. Frequent players account for more than 70 percent of all expenditures in tennis, including buying equipment, paying for lessons and court time, and playing ...
https://www.athleticbusiness.com/recreation/why-tennis-and-running-are-growing-in...