For a deer that has been thoroughly deboned (rib meat too, as I do) about 50% is the yield. I would get a little more meat than 25 pounds from a 60 pound fawn in our area. Not sure how big deer are by you. If you deer was bigger, they probably did not bother with a lot of the trimmings, and those trimmings add up.

Not sure what living in the city has to do with butchering. I hang my deer in the garage and butcher mine in the garage as well. Unless you have no garage I suppose. I debone and then take to a reputable butcher to mix with some beef and made into burger - and I weigh it myself, and let them know how much it weighed, just to keep them honest.