@double naught--I only know what I saw on a special news segment on TV where they interviewed the officer in charge of monitoring the pawn shops in our area. As I recall, the officer described the sheer volume of both number of shops as well as items moving through them as something they had trouble keeping up with. Literally books of serial numbers that needed to be matched with stolen ID items. I seem to recall the percentage of goods that were of possible stolen origin as being higher than the number you have, but still not that significant in terms of the overall volume of goods moved. I'll admit it was an exaggeration to imply that the copious number of pawn shops was due to stolen goods being actively fenced through the shops--but I suspect that there is a way to "launder" the goods so it is hard to trace or be claimed, but I have no proof of that, so it is just speculation.
Even criminals obey the laws of supply and demand.