A chance of an event is always the same for each event, unless some new information comes along say the likelyhood of an event changes.

If you're going to say that Florida "keeps getting hammered" or the Mid-West is always getting flooded, then maybe you should start saying "all large congregations of people are terrorist targets". With that thinking, everyone in the country should be dispersed.

Or, a novel idea, you could just try and mitigate the threat and just live life.