"These decade-long averages suggest that the prevalence, if not the deadliness, of “mass public shootings” increased in the 1970s and 1980s, and continued to i

"These decade-long averages suggest that the prevalence, if not the deadliness, of “mass public shootings” increased in the 1970s and 1980s, and continued to increase, but not as steeply, during the 1990s, 2000s, and first four years of the 2010s." https://fas.org/sgp/crs/misc/R44126.pdf https://fas.org/sgp/crs/misc/R44126.pdf