Thanks everyone. It's nice to have others appreciate your accomplishments regardless of how small they are.

Meaningful comparison of mph speed depends a great deal on how many/how high hills and inclines or even how many curves and turns there are in your ride- is that correct or am I missing the boat?
Comparison between others - that's true. But I ride the same 4 or 5 routes all the time and my avg speed as a rule has been between 14.2 to 14.8 mph. Getting my avg speed up to 15 mph on any given ride is my goal...so anytime I can get over 15 mph avg I'll be happy. But seeing 15.6 was just way beyond my expectations.