Ian,
As much as I respect your reasons for the paper, I would like to suggest an alternative approach. Polling forum members can be quite arbitrary and give misleading results since you may not hear from everyone who attends recurrent training. An option, or even a parallel path for comparison may be to poll area training facilities and individuals who perform training. I believe you can achieve a much more accurate result with regard to people trained with this approach. Some facilities may not wish to divulge specifics such as women attendees, LEO training, initial membership training required by gun clubs, Oregon or Utah CHL, or defensive handgun training, etc. Even without specifics, you can probably get a more accurate count.
I believe that some of us on the forum would be interested in your results and may even be willing to use your poll, with your permission, when we write to our legislators.
Good luck with your paper.