Well, it doesn't really matter if it's your foot or a sack with 20lbs of Big Mac's pushing the pedal, the average is still the same.
I believe the average was around 20MPG for the N/A and just a little more for the Turbo.... given age I think the typical range I've seen is between 17 and 20; There are a lot of factors to consider though: age, mechanical and electrical condition, altitude, fuel grade, air temp and humidity being the biggest.