I don’t think there is much data to be had, at least public. But I can tell you in the 5 years my brother has been there, they have had zero armed robbery attempts, and several employee theft attempts. And a quick Google about whether dispensaries get robbed frequently will show you people from the industry saying the same thing.
But no, no data, only anecdotes. Still, I feel like only somebody who has never been in a dispensary would think they are attractive robbery target. I’ve been in them and maybe 10 states, and they are all pretty tight Security, because they know they have a lot of cash and people would like to steal it.