Wikipedia, the “multilingual, web-based, free-content encyclopedia project,” was created in 2001 and celebrates its tenth anniversary on January 15, 2011.

The percentage of all American adults who use Wikipedia to look for information has increased from 25% in February 2007 to 42% in May 2010, a 17 percentage point increase. The proportion of adults who use the internet over that same time period grew at a more modest rate, from 71% to 79% of all adults.

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