Number of American adults who had used tai chi within 12 months of a 2007 study:

2.3 million
According to a 2007 study by the National Institutes of Health.
Source: USA Today, 8/19/2010

  Number of U.S. states which have a state high school championship tournament in judo:

As of November 2009, Hawaii was the only state in the U.S. to offer a state high school championship in judo.
Source: USA Today, 11/6/2009

  Number of Britain's Anglican clergy offered martial-arts training by their union in 2002:


Source: MSF, 9/23/2002

  Percentage change in the number of children enrolled in martial arts classes between 1988-1994 in the U.S.:


Source: Harper's Magazine, 2/27/1994