If you didn't know this, you should: violence per capita has been on a downward trend
throughout human history, on both a macro and micro scale:
[...]if we consider the evidence, we find that the decline of violence is a fractal phenomenon: We can see the decline over millennia, centuries, decades, and years. When the archeologist Lawrence Keeley examined casualty rates among contemporary hunter-gatherers—which is the best picture we have of how people might have lived 10,000 years ago—he discovered that the likelihood that a man would die at the hands of another man ranged from a high of 60 percent in one tribe to 15 percent at the most peaceable end. In contrast, the chance that a European or American man would be killed by another man was less than one percent during the 20th century, a period of time that includes both world wars. If the death rate of tribal warfare had prevailed in the 20th century, there would have been two billion deaths rather than 100 million, horrible as that is.
We also have very good statistics for the history of one-on-one murder, because for centuries many European municipalities have recorded causes of death. When the criminologist Manuel Eisner scoured the records of every village, city, county, and nation he could find, he discovered that homicide rates in Europe had declined from 100 killings per 100,000 people per year in the Middle Ages to less than one killing per 100,000 people in modern Europe.