That would be hard to keep track of, simply because most cases of "crossfire" happen between people who are already using illegal (or illegally acquired) guns... such as gangs and criminals. The chances of collateral damage from law abiding citizens who carry guns are much lower because:
- they care about innocent people.
- many of them train on using their guns properly and assessing what's between them and the target and also behind the target.
If you think that people who carry concealed just whip out a gun and start shooting randomly, you must not know any of these people.