Here's what I've found so far.
http://www-nrd.nhtsa.dot.gov/pdf/nrd...01/809-360.pdf
www.webs4racers.com/crash/about%20crashes.htm
This material was found searching Google using "motorcycle accident statistics". The first URL takes you to a fairly recent study that only deals with fatalities. Won't help you much but worth checking out in case "leadership" decides to cite this study.
The second one includes a summary of the Hurt Study done in 1981 that seems to be more in depth than the more recent fatal accident study. Check out item number 52, which states that "...Motor vehicle...data contains information which is completely unrelated to actual use." That backs up your argument very well.
And while item 40 mentions that "injury severity increases with...motorcycle size", number 30 points out that "The large displacement motorcycles are under represented in accidents but they are associated with higher injury severity when involved in accidents."
It is important to remember that this study was done in the early eighties, so item 30 is out of date in that the higher speeds and greater acceleration associated with larger displacement in those days are now attainable with relatively smaller bikes.
If I were in your position I would stress the need for training, zero tolerance for alcohol while riding ("leadership" will get a boner over the zero tolerance line), mandatory helmet use, and anything else that will cut down on the occurrence of accidents/injuries rather than simply trying to shoot down the ridiculous cc restriction.
My take on the whole issue is that folks who are willing to fight and maybe die for our country should be able to ride whatever the heck they want, just like everyone else!
Good luck
JR