Only ten…?
Those would be the ones that we know about because 1) they killed someone; 2) it wasn't workplace violence even though they were yelling "Mohammad is the bestest pig humper"; 3) they didn't pay the Clinton Foundation enough money; 4) they were actually caught; 5) someone didn't post their bail; 5) it was determined they weren't mentally unstable so therefore it couldn't have been terrorism; 6) they didn't use a pressure cooker because that was just because they failed their cooking class and the unit exploded unrepentantly; 7) ...
So eventually, you only end up with maybe ten, I am actually surprised that it is even as high as ten.