Source  http://npd.snd.org/
Related posts:
Roman Racetrack [Infographic]
World's Top 100 Universities
Interactive - 2010 a Year in Review
The Cost Efficiency of Transportation [Infographic]
Getting the Most from the Job Market [Infographic]
List of Current National Football League Stadiums [Infographic]
Dangerous Areas of The Natural World
Solar System Infographic
Why Prolonged Sitting And Standing Is Unproductive – Infographic
Solar System Temperatures - Nasa.gov