[cop359]

The data on that graph looks bogus to me. I doubt they'd be able to assess per capita GDP year to year so accurately for the years before 1900.

Take for example the Taiping Rebellion which was from 1850 to 1864. Described by wikipedia: "About 20 million people died, mainly civilians, in one of the deadliest military conflicts in history."

Yet according to that graph is had little to no effect of the per capita GDP.