Horrible idea. It would be far more likely a teacher would accidently shoot a student than ever even be in a position to defend them, let alone qualified to act.
You have statistics to support this?
How many armed teachers have accidentally shot a student?
Having a concealed carry permit does not mean your are even vaguely competent with a firearm.
Neither does carrying a badge and police credentials -- but you have no issue with cops carrying guns.
Police go through extensive and ongoing training. It is not the same thing as spending a couple of hours shooting at targets. Police have to actually qualify, the CC student only has to show up. I have three cards myself, and not one of them required I demonstrate I can hit anything.
There is an old saying that guns don't kill people, people kill people. That is true. It is also true that guns don't save people, people do. The idea that putting a gun in the hand of an untrained and untried person, in the middle of a bunch of children, and they are going to suddenly turn into John Wayne in an emergency is pure fantasy. The most likely scenario is they are just going to be another source of wild firing. And that does not address the issue of the weapons being in the school to begin with, loaded, unlocked and accessible. If you don't see the potential for disaster there then you really need to start thinking. Not everything in the movies is real.
There are no stats on this because the stupidity is only just beginning. When the stats begin, I'm sure people will find someone to blame it on.