From a recent study in which they anon-polled athletes:
"More than 2,000 track and field athletes participated in the study, and according to the findings...an estimated 29 per cent of the athletes at the 2011 World Championships and 45 per cent of the athletes at the 2011 Pan-Arab Games said in anonymous surveys that they had doped in the past year."
And That's 45% that ADMITTED to doping.