What the Wapo?
Here's an article to muddy the waters for you-
Read the whole thing
I doubt it's 90% and I doubt it's 17%. My guess is it's somewhere in between and we'll never know that number or an accurate number regarding the amount of drugs headed north.
For the record I like guns too. But I think most of the weapons being used come from the US. Rocket launch attacked and military grade weapons are no that common here, pistols and rifles are. But them again "los Zetas' the current biggest player prefers to cut heads off and hang bodies from building and bridges. Don't need a gun for that. Just a good knife and some rope.