Well it all depends. This year with letting areas being grazed, and hayed it will focus the hunters all to less habitat. With fewer birds they will receive more pressure, and after getting pushed out / shot at a couple times they will find a private fence line to call home. It's common for the public land birds to spend the whole day out in fields/ marginal cover where you can't get close to them, only returning to the public grass at dusk. So miles walked to in range shots can be poor. I know it's not the answer your looking for, but there are too many variables especially weather conditions to give a number.