"More students have repeated cannabis use (3 times or more; 7.8%) than they have only used 1-2 times (5.6%). Boys repeated cannabis use in significantly higher proportions compared to girls (11.1% and 4.4%, respectively). Repeated cannabis use (as opposed to 1-2 times use) increases after the age of 16. Finally, students in Athens and Thessaloniki repeat cannabis use in significantly higher proportions compared to other areas (10.6%, 11.1%, and 5.4%, respectively) (Table 2.2)."

Source

University Mental Health Research Institute, "2012 National Report (2011 Data) to the EMCDDA by the Reitox National Focal Point: Greece: New Development, Trends and in-depth information on selected issues" (Athens, Greece: UMHRI, 2012), p. 31.
http://www.emcdda.europa.eu/h…
http://www.emcdda.europa.eu/a…