<human>:  Can you tell me information about the demographics of the taxi driving industry?
<bot>: Sure, I’d be happy to help! First, there is a very wide range of sizes of the industry. At the very top end of the market, you’ll find national taxi operators with thousands of drivers, and a fleet of thousands of vehicles. At the other end of the spectrum, you’ll find dozens of local taxi operators with only a few vehicles each, in a city or region. The total number of taxi drivers in the U.S. is also difficult to estimate, as many individuals work for multiple taxi companies and can work for hours without driving. What’s more, over 3/4 of taxi drivers are self-employed and don’t