I find that a little hard to believe...
I found it hard to believe when I first saw the numbers.
I believe I first saw the figures in a 1996-2000 FBI report on sexual assault; the FBI put the average number of victims somewhere just north of 200.
According to this site, the Sexual Assault of Young Children as Reported to Law Enforcement: Victim, Incident, and Offender Characteristics, by Howard N. Snyder, Ph.D.; National Center for Juvenile Justice, July 2000, U.S. Department of Justice, Office of Justice Programs reports an average of 52 victims for male molesters of girls, and 150 for male molesters of boys.
This California Report claims that the average male molester of boys has 100 victims.
This website lists several studies and states that pedophiles have an average of 250 victims.