My daily ride of 20-25 miles of rolling hills is between 12-14 mph depending on wind and how I feel.

I rode 70 miles Saturday morning on the local paved bike path (flat) and averaged a fuzz over 14 mph for 4 hrs and 55 minutes.

Speed, for me anyway, doesn't come over night. I'm riding 400 miles per month and just hit 1600 for the year (starting March 7th). I am just now able to notice a bit of a difference. The wind and the hills are getting a bit easier every few weeks.

Looking back however, I was happy with 10 miles at 10MPH when I first started.