So far in the US, in 2015: 353 mass shootings (as of the 337th day of the year). 462 dead. 1,312 injured. All stats derived directly from Mass Shooting Tracker. (Why do we even have a site called Mass Shooting Tracker?)
I am going to drop firmly into opinion mode and say bluntly: The assertions of the gun-nutter set -- that citizens are defending themselves against crimes at a rate that somehow justifies all this carnage -- are blatantly false, whether or not that is intentional on the part of any given speaker. In other words, I don't consider that everyone who repeats lies is a liar. Some are just dupes.
But lies are controlling our policy about guns.