I was thinking this year I was slower than last until I looked at last years rides and found I was just the same.
It is hard to say where I am compared to others and to be honest I don't care. I ride as much as I can, 4-5 times a week sometimes 6. All seem to be around 30 miles except on weekends where I like to go beyond that and all seem to average between 17 and 18 mph. So there you go.
All my rides are solo as well.
edit: forgot to vote