98% of mass shootings take place in “gun-free zones”..
From 1950 through July 10, 2016, only 1.6% of mass shootings took place in areas where guns were allowed to be legally carried.
Crime Prevention Research Center,
Looks like they cherry picked the data to get a result they wanted. Using only 21th century data still includes the recent Las Vegas shooting and eliminated a lot of data from last century.