UFO sightings and military bases - question

I'm guessing that this has been covered before. I've tried to locate the thread and have been unable to, so if someone can point me in the right direction, I would appreciate.

Has any analysis been done to correlate sightings and the proximity of those sightings to military bases? I live very close to both an Air Force and Army base and there are often reports of strange objects. Many of these can not be explained and on at least three occasions when different friends of mine who live on a lake called and reported seeing three spheres hovering over the lake, moving laterally and vertically and then with a speed that would be inconsistent with any known aircraft, the police were at their doors within minutes. Way to quickly for a normal response, almost as if they expected the calls. All of my friends got the same take from their conversations with the police. That they knew what was going on. Are there more reports of this type closer to bases than in other areas?