"In 2006, the Sloan Consortium reported 700,000 enrollments in K-12 online learning. According to the Sloan Consortium, the overall number of K-12 students engaged in online courses in 2007-2008 is estimated at 1,030,000. This represents a 47% increase since 2005-2006."
Source: K-12 Online Learning: A 2008 Follow-up of the Survey of U.S. School District Administrators, Sloan Consortium, January 2009.