But as a proportion of the (dropping) violence, you're right - more are more is drug related.
Nothing new about that - in the US nearly half of all prisoners are incarcerated on drug charges.
Yet nobody seems to learn. The Feds just keep moving from one drug panic to the next - each time creating a new crop of black market violence and non-violent prisoners. This week it's Oxycontin - next week, something else.
Maybe by your definition I'm part of the problem, but I see a big difference between the level of scrutiny required for a business vs. government.
A government can imprison me, fine me, take away my business, take my passport, keep me from getting on airplanes, and kill me. It can tell me what I must and must not eat, and what drugs I must and must not take. It can tell me who I may have sex with, and how, and who I can marry. It can take away my children. It can send me and my children to war.
No business can do ANY of that.
If I don't want to deal with a business, I don't.
If I don't want to deal with the government, I ... go to prison.
So there are lots of things that I find acceptable for a business to do (because, who cares), that are NOT acceptable for a government to do.