I have a couple of comments.
First of all, on the issue of discretion and the percentage of offenders who are in the national registry, one of the things I would suggest is that you try to get a very clear sense of why you're not capturing a higher percentage. Would a reasonable person look at it and say that these are cases in which the judge reasonably exercised discretion? Are these cases of plea bargain, or cases of the prosecutor not even asking?
So you should have a clear sense of why you have a much lower percentage.