Hello, folks, it's Maura again.  I am afraid I am not a statistician,
so I am really not familiar with the kind of analysis you are asking
for.  We do collect standard annual service data from our chapters,
such as the number and types of disasters to which they have
responded, the number of people they have trained in first aid, CPR,
disaster preparedness, etc.  We know how many people donate blood (a
frighteningly small percentage of those who are eligible).  Today is
Saturday and I am replying from home, so I don't have access to the
numbers at the moment.  Maybe you could provide me with a link to an
explanation of what you have in mind.
Before I close, I just want to say that the blood supply is always low
around the holidays because people are busy.  So if you can donate,
please do.  You truly could be saving lives.  And please be careful
about fire safety this holiday season.