This and other numbers can be found in the Alliance 2010 Benchmarking Report, an good resource and tool for government officials, advocates, and those working to promote bicycling and walking in de USA.
The report also highlights the fact that states with the lowest levels of biking and walking have, on average, the highest rates of obesity, diabetes, and high blood pressure. In contrast states with the highest levels of biking and walking have, on average, the lowest rates of obesity, diabetes, and high blood pressure. In addition, where rates of biking and walking are greater, more of the adult population is likely to achieve the 150 minutes of weekly moderate-intensity aerobic activity recommended by the Centers for Disease Control and Prevention (CDC). According to CDC, physical activity can reduce your risk of dying early from the leading causes of death, like heart disease and some cancers.
The Benchmarking Project is an on-going effort to collect and analyze data on bicycling and walking in all 50 states and the 51 largest U.S. cities. It can be downloaded at: http://www.peoplepoweredmovement.org/site/index.php/site/memberservices/C529