Answer: from 8 percent to 20 percent

The National Center for Education Statistics (NCES) released a report called Learning at a Distance, which also said the number of students who were enrolled in 100 percent online degree programs rose from 2 percent to 4 percent between 2000 and 2008.

According to the report, the main benefits of online courses are that students don't need to commute, and they can learn and complete assignments on their own time, which ultimately allows for greater flexibility.

Read more about the report at the NCES website.