* The number of people killed in battle – calculated per 100,000 population – has dropped by 1,000-fold over the centuries as civilizations evolved. Before there were organized countries, battles killed on average more than 500 out of every 100,000 people. In 19th century France, it was 70. In the 20th century with two world wars and a few genocides, it was 60. Now battlefield deaths are down to three-tenths of a person per 100,000.
* The rate of genocide deaths per world population was 1,400 times higher in 1942 than in 2008.
* There were fewer than 20 democracies in 1946. Now there are close to 100. Meanwhile, the number of authoritarian countries has dropped from a high of almost 90 in 1976 to about 25 now.