You can probaly write off a few to death (cars, other hunters nearby, injury), a few to changing location, and maybe some using the 230 acre sanctuary more. Even if the property hasn't changed their enviornment has in that even if you are very careful about scent and what not(which you seem to be) you took quite a few deer out of there and tracked and trailed and searched for at least one other I thought(can't remember exactly). That could account for some of the change as well.

I huntone piece that is a similiar size(67 acres) and even though I am very careful they can still pattern me it seems. They know what's going on in those woods very well.