I recently came across this stat from jdpayne.org on youth sports.
In 2006, 41% of 6 to 17 year olds participated in sports. This number is up from 34% in 1998. Sports was the most popular extracurricular activity. http://www.census.gov/newsroom/releases/archives/children/cb09-182.html
Almost half of youth are participating in sports! Statistical proof for what we already knew: sports is a great context to reach your community with the gospel.