Seeing data for where a vendor ships over their career would be fucking awesome. It would give us such a good picture of which drugs are more popular where and where drugs are more popular in general. If it also showed quantities we could see where the streets are most dangerous for buyers and where the biggest market is for sellers.
Unfortunately sharing this data would fuck both the vendor and the buyers. A man can dream though.
Sounds like an LE's wet dream....and I would bet that the demographics fluctuate quite often, depending on not only local supply, time of year, but things like events that are happening in that area (from concerts, to gang wars an of course droughts) - all the way to busts.