That's the whole problem with a straight PP system if you don't get in on the ground floor when one is started and you are looking at drawing some of the top units. Before long it's a few points for a number of the units and then a huge psread of Pps to the top ones that may take 10 years to life---look at CO, UT, or the sheep and moose PPs in WY as an example! The turnaorund on max PP people is longer than most will live!