Yeah. The first chart seems strange too. It says the world in the 20th century had 6 violent deaths per 100K people per year, so the number of violent deaths should be 6 * 100 * average world population / 100K. But taking average world population as 4B, the number of violent deaths comes out as 24M, which seems smaller than WWI + WWII + all other wars and mass killings.
Yeah. The first chart seems strange too. It says the world in the 20th century had 6 violent deaths per 100K people per year, so the number of violent deaths should be 6 * 100 * average world population / 100K. But taking average world population as 4B, the number of violent deaths comes out as 24M, which seems smaller than WWI + WWII + all other wars and mass killings.
Now that you mention it, this number does seem to undershoot the death count.