Partially because of Dartmouth's rural, isolated location, the Greek system dating from the 1840s is one of the most popular social outlets for students. Dartmouth is home to 32 recognized Greek houses: 17 fraternities, 12 sororities, and three coeducational organizations. In 2007, roughly 70% of eligible students belonged to a Greek organization; since 1987, students have not been permitted to join Greek organizations until their sophomore year. Dartmouth College was among the first institutions of higher education to desegregate fraternity houses in the 1950s, and was involved in the movement to create coeducational Greek houses in the 1970s. In the early first decade of the 21st century, campus-wide debate focused on a Board of Trustees recommendation that Greek organizations become "substantially coeducational"; this attempt to change the Greek system eventually failed.