Why don't you think it's possible to get 100 moles off 52 acres ? If the area and surrounding land has had no control, then I think it would be possible to be round the 100 mark. I did a 1/2 acre lawn couple weeks back and got 15 in 3 visits.
have you seen this place, didnt think so, i have had 32 moles of a small domestic garden in 2 weeks, had 147 off 1200 acre, dont matter what size the land is if there is plenty of food then the moles can thrive