The share of college students taking online courses has grown, up by about 6 percent, even as the overall number of people enrolled in higher education institutions dropped by about half a percent. According to preliminary numbers issued by the U.S. Department of Education's National Center for Education Statistics, of the 20.1 million students enrolled in fall 2017, 6.7 million were taking at least one distance education class, representing 33 percent of the total — a boost from 31 percent in the previous year.