Welcome to WebmasterWorld Guest from 18.104.22.168
This makes me a little nervous because it might appear to Adsense that there is some monkey business going on with the clicks. I wondered if anyone else has a similar site where a lot of the visitors are from a local area. And whether that has gotten them dropped from Adsense?
Remember, there are many different IP numbers due to different ISPs. Unless you live in a small town that only has access to one ISP for everyone, this should not be an issue.
AOL has a block of IP numbers
DSL has a block of IP numbers
Cable has a block of IP numbers
Netzero has a block of IP numbers.