A 2015 report shows an increase in the popularity of online undergraduate courses among under 25-year olds. This is due in part to increased pressure to continue working while studying, and familiarity with online courses.
The article and link to the full report can be accessed here: http://www.usnews.com/education/online-education/articles/2015/07/17/younger-students-increasingly-drawn-to-online-learning-study-finds