Homicides Over Time, Plus a Question About Drugs

I was looking for information on drug related murders and inadvertently stumbled on this old Bureau of Justice of Statistics report. There’s a lot of interesting information in it. One fascinating table is this:

For context, here is the population breakdown over a period that includes the timespan in the table.

I’m not sure this gives enough information to say what would happen if drugs were legalized, but I am interested in your thoughts.