Skateboarding has been shaped and influenced by many skateboarders throughout the years. A 2002 report by American Sports Data found that there were 18.5 million skateboarders in the world. 85 percent of skateboarders polled who had used a board in the last year were under the age of 18, and 74 percent were male.
Skateboarding is a relatively modern sport. A key skateboarding maneuver, the ollie, was developed in the late 1970s by Alan "Ollie" Gelfand as a half-pipe maneuver. Freestyle skateboarder Rodney Mullen was the first to take it to flat ground and later invented the kickflip and its variations.
Most boards are about 7¼ to 8 inches wide and 30 to 32 inches long. The wheels are made of an extremely hard polyurethane, with hardness (durometer) approximately 99A. The wheel sizes are relatively small so that the boards are lighter, and the wheel's inertia is overcome quicker, thus making tricks more manageable. Board styles have changed dramatically since the 1970s but have remained mostly alike since the mid 1990s. The contemporary shape of the skateboard is derived from the freestyle boards of the 1980s with a largely symmetrical shape and relatively narrow width. This form had become standard by the mid '90s.
Go Skateboarding Day was created in 2004 by a group of skateboarding companies to promote skateboarding and help make it more noticeable to the world. It is celebrated every year on June 21st.