There are books on it. Just quick search found sources. Believe to narrow down what is meant by violence , it is all violent deaths, by war or murder. https

There are books on it. Just quick search found sources. Believe to narrow down what is meant by violence , it is all violent deaths, by war or murder. https://www.scientificamerican.com/article/history-and-the-decline-of-human-violence/ https://www.scientificamerican.com/article/history-and-the-d... https://stevenpinker.com/publications/better-angels-our-nature https://stevenpinker.com/publications/better-angels-our-natu... https://fivebooks.com/best-books/decline-violence-steven-pinker/ https://fivebooks.com/best-books/decline-violence-steven-pin...