[anthrovolution]

I don't know what the averages are yet. I haven't played with the results long enough. From what I can tell so far a relatively save zone would be 4 to 6 risks that are all over 100 miles away. If you have dozens of risks less than 50 miles away then I would call that a risky area. A lot more research needs to be done, however, to come up with a good criteria.