I too have wondered what physical attendance at my old K.H is like now, two Congregations use the Hall, and I have no way of knowing what the official Publisher count is for them. But back when I was in there was always 25% of that number missing at any one meeting, different folks each time, but that figure was about constant.
What is of greater interest to me is the number who have left since I did, over a decade and a half ago, others have died of course, and I cannot think they have been replaced by converts, so I am thinking the two Congregations in reality are no larger than when I left.