Between the 1999 Columbine High School massacre in Colorado and the 2012 Sandy Hook Elementary School shooting in Connecticut, there were 31 school shootings in the United States and 14 in the rest of the world combined. Between 2000 and 2010, counting incidents from 37 countries in which someone was injured or killed on school grounds, with two or more victims, and not counting “single homicides, off-campus homicides, killings caused by government actions, militaries, terrorists or militants”, the number of such incidents in the United States was one less than in the other 36 countries combined; in the vast majority of the United States incidents, perpetrators used guns.