That's vastly incorrect. There have been 34 mass shootings this year alone in America, and we're not yet at the end of February. There were 346 mass shootings last year..
Go edit Wiki then. I assumed that their figures and definition were broadly correct:
"The United States has more mass shootings than any other country. A mass shooting is commonly defined as a shooting resulting in at least four victims, excluding the perpetrator. When the definition is restricted to four or more people killed, data shows 146 mass shootings between 1967 and 2017, with an average of eight people dead including the perpetrator. The perpetrator generally either commits suicide or is killed or is restrained by law enforcement officers or civilians."
Other categories of shooting are not central to the original debates, which were focussed on random shooting spree murders in schools or workplaces.
The article on overall gun violence seems quite comprehensive:
Gun violence in the United States - Wikipedia
Whether the broader US population really are justified in running scared is debateable, given that the chance of becoming a non-gang related shooting casualty is about a quarter of that of becoming a road accident fatality - something that most people tend not to even contemplate on a day-to-day basis.