Cluster with high numbers of calls

Today I have shown the same graph that I published yesterday and highlighted my first cluster points in green. I have then mapped these grid squares below. These grid squares represent the the busiest areas for "I" calls in 2009. Within this cluster there is a small negative correlation between the two variables of -0.22 meaning there is a tendency for grid squares with more calls to have a better average response time than those with fewer calls. My initial hypothesis for this, which may be shown to wrong, is that these grid squares are ones with high numbers of pubs, clubs, shops and transport hubs - places where people congregate, that is, not predominately residential locations. This would account for the high number of calls and the fact that police respond quickly. These are places where police tend to patrol, they are easy to get to because they tend to be on main roads, and the call venues tend to be well known so there is no delay in finding out where they are.