Some clues :
Douglas P. Fry : Pacified Past
Azar Gat : Warfare as an Ancient Feature
Robert L. Carneiro : Complexity and State Formation
Was the 20th century one of the most violent in human history ? (with two world wars and numerous other conflicts) ?
i also like the documentary series : “The Ascent of man” from the BBC in 1973 by Jacob Bronowski.
Your graphic doesn’t go past 2011.
I couldn’t find that exact graph to the 2020s, but here are some more.
Thanks. That last graph seems the most relevant. Kind of wild how the regions changed so drastically in the last couple years there.