But c'mon, hopefully people don't really think school shootings are the only ones that count? As mentioned, the problem is gun violence. School shootings are a symptom.
If you want to think about numbers of shootings look at something like http://www.gunviolencearchive.org. We are two months into 2018, and the USA is sitting at 9000 incidents, 2400 deaths, 4000 injuries.
For more shooting rates fun facts consider https://www.npr.org/sections/goatsandsoda/2018/02/15/586014065/deaths-from-gun-violence-how-the-u-s-compares-to-the-rest-of-the-world . The good news is, the death rate by violent shooting in the US is still less than in Iraq! Unfortunately however, the rate in US is twice as high or higher than places like Syria, Jordan, Yemen, Pakistan. etc. etc. lots of good company there. Or maybe we should pat ourselves on the back for still having a lower rate than El Salvador, even though we are the undisputed champion of the world in guns per capita (https://www.cnn.com/2017/10/03/americas/us-gun-statistics/index.html).