Tables of Death
This is the table of casualties kept by the government in London, England during the seventeenth century.
Looking at the table, I noticed a peculiar trend. My theory is that the number of murders occurring during a year is correlated with the number of headaches people are experiencing. I made this graphic to help explain.
Turns out, the spike in murders and headaches might only been caused by the political unrest in England as parliament was disbanded by Richard Cromwell disbanded and eventually reformed. Nonetheless, the rest of the data might still confirm my theory.
Also, it's a little difficult to see with the lower resolution image, but the darker bars on the left of each pair show the number of headaches and the lighter bars represent the number of murders.