Twelve percent of Americans—about 47 million people—bicycle on a regular basis. Forty-four percent of bicyclists are between the age of 30 and 64. In 2015, in the United States, over 1,000 bicyclists died and there were almost 338,000 bicycle-related injuries. Data shows fatal and nonfatal crash-related injuries to bicyclists result in lifetime medical costs and productivity losses of $10 billion. A meta-analysis of bicycle helmet efficacy by Attewell, Glase, and McFadden estimated that bicycle helmets reduced the risk of brain injury by 58%. (Accid. Anal Prev 2018 Aug;117:85-97. doi: 10.1016/j.aap.2018.03.026. "Bicycle helmets—To wear or not to wear?) Which suggests that 42% of brain injury was not protected by helmets. In the United States, more than 13 million people regularly ride motorcycles. Helmet use in motorcycling generally reduces the risk of death by 37% and reduces the risk of head injury by 69%. Over 5 million Americans play football and about 50% of all sports concussions occur in football.