There's a LOT more to latency than distance. Your ping can be determined by any combination of local bandwidth traffic, number of hops (quantity of transfer points) to and from the server, and upload/download activity on your computer/network.
If your ping is consistently around 200, then you're likely going to be stuck at about that amount. However, if your ping fluctuates greatly from time to time, and day to day, it's likely due to internet traffic and time-of-day activity. Either way, try to make a note of what your ping appears to be at certain points of the day, over several days, so that you can better diagnose the issue.