The 9% to 10% is really based on the most recent study that was published by the Correctional Service of Canada. They did a prevalent study in June 2011. There are other studies that have generated retrospectively; in other words, they have gone back afterward and looked at populations and they've said, okay, we find the prevalence to be 22%, 23%, 24%. There are different studies using slightly different methodologies to determine the population.
The Correctional Service Canada prevalent study that found the 10%, or the just under 10%, also found another 15% where file information was incomplete. People exhibited many of the characteristics, but they couldn't confirm or deny a diagnosis. Even in the CSC study, which only finds 10%, they suggest it could be another 15%, bringing you back to the one in four or 25% for the prevalence of FASD.
Interestingly, they also found 45% of offenders, who weren't FAS-disordered, had other neuropsychological deficits.