Comment by RobAtticus

That seems unlikely. The first graph[1] on this Wiki[2] article shows from 1982 until 2017 -- so not the exact range you mentioned -- but it shows that mass shooting deaths are higher today than decades ago.

[1] https://en.wikipedia.org/wiki/Mass_shootings_in_the_United_S...

[2] https://en.wikipedia.org/wiki/Mass_shootings_in_the_United_S...