Wow, I found that a very powerful and persuasive article. One question is why don't they show the stress index from 1870-1940? Stress obviously went up during t

Wow, I found that a very powerful and persuasive article. One question is why don't they show the stress index from 1870-1940? Stress obviously went up during the civil war, but was there relief after? Stress prob. went down in the 1920s but up by 1930.