Source is [1], 45k / 1290k for drug possession (and nothing harder), plus 145k for other drug charges (which I guess is closer to 11% not 10% as I said).
Minnesota's 17% isn't that far off the national number it seems. They don't give a breakdown for simple possession. Violent crimes at 55% are again a majority.
You're going to need to source that unbelievably low number.
In my state, drug crimes represent the second largest proportion of prison inmates - a bit fewer than criminal sexual conduct a bit more than homicide: https://mn.gov/doc/assets/Adult%20Prison%20Population%20Summ...