Your comment made me wonder about generational differences when it comes to drugs of choice, since psychedelics seemingly fell out of favor there for a bit while cocaine took over. I wonder how each generation's drug use affects their consciousness and such. Some random data:
Nice work. What if it was a line graph with x as the year, y as the percentage, and each line representing the different drug class? Would that be too many lines?
That's great! Its not perfect but it quickly shows that cocaine and pain killers are the real ones making moves. Hallucinogens don't appear to have changed much.