It is a little low, but as a general rule of thumb you should have 10PSI for every 1000 RPMs. Mine is about the same, but is about 25 at hot idle and maybe 40 during normal driving.
I don't understand the whole 10psi for every 1000 rpm thing. The pressure does not act consistently with rpm, meaning at idle you can have 25psi, and a lot of engines get 40+by 2000 rpm and never go over 60 by the time they are at 6000rpm. Can someone elaborate on that, because I have seen a lot of people say that.
The ultimate pressure is controlled by the relief spring in the pump, operating pressure is effected by bearing clearances and oil weight. That also depends on the pump, some have adjustable relief springs, etc...
If the bearing clearances are wide or the rod side clearances it will show lower pressure, the important thing is that is raises when more throttle/rpm is applied. This is where a higher volume pump can come into play, higher pressure pumps can also help but it all depends on what the motor was set-up for.