I’d like to see it as a fraction of GNP, GDP, or even per capita and adjusted for inflation. I’m also not thrilled that they top out at $500B for a country, not when our annual deficit is more than twice that value and our debt is 30 times as big. That makes most national debts look equal, even when the differences are both huge and meaningful.
Very good point. The data in the graphic is also (based on the image URL) two years out of date.