what should I be aiming for for WOT RPM on a 2000 Johnson 175 on a 19' Javelin Renegade?

took my boat out for it's first ever (for me) ride, and I only had 15 # of water pressure at high rpm and 10 at 3500 rpm. seems low....

no jack plate, motor in the second hole from the bottom (higher than mid point)