My take on it is this. I think that there is an inordinately high density of stingrays around Bunces Pass. I have theories as to why, but who cares. I think that for the SPB area in general, being stung is not nearly as likely as being stung at North Beach in the summer.
I wish I had the numbers on how many people have been stung along the entire beach, from CLW to SPB, in the last month. I would be willing to bet that per square mile, NB has a very high density of hits compared to surrounding areas. You would have to do it as man hours in water/square mile or sumtin' to factor in numbers of people in the water.
I think it's unlikely that many people have spent as much time walking in waist deep or ankle deep salt water environments as I have. I am talking literally thousands of hours. Even so, I wasn't stung prior to last weekend. So, in general in your "average area", I think the odds aren't high of being hit by a ray.
But, ... I think I will take a pass on walking the shallows off of NB anytime soon.