New vs Returning ratio

[Allfetish]

What do you see as an acceptable ratio of new vs return visitors? I take it this is an important metric in determining how well what you are doing is working in regards to keeping the visitors interest.

After about a week two blogs (each about 1,000 visitors per day) have the following:

Blog 1: 16% returning
Blog 2: 9% returning

What should I realistically be shooting for here? What do you see with yours?

Also a side question, using Google Analytics stats, does anyone know how to see stats on average as to how often returning visitors are coming back per day? I want to use this to determine whether an extra update would actually help.

Thanks!