The rural congregation I grew up in has no new members since I was there in the 70's and 80's. It's the same old people... litterally. Pretty much all the younger ones (ie the ones I grew up with) have moved away to take jobs elsewhere, or were DAed/DFed.
That congregation merged with a second congregation nearby (80km between halls) that had the grey hair problem way worse than my former cong... so that bolstered the numbers a little, for a while... until those people literally died off from old age. The area that second congregation covered is now "uncovered" so to speak... no congregation anywhere nearby... its terretorry is unassigned.
My family have moved to a nearby city, and are in a cong I knew well in my youth. As a family we had good friends living in that city,and we'd go visit them fairly regularly, and attend the meetings there. I got to know a lot of people in that cong over the years - this is also in the 70's and 80's. When I last visited my family, they dragged me to the meetings. Since I'm a fader, I went along and pretended as much as I had to, to get through it... what struck me was, the people at the meeting... it was all the same people I knew from my youth... it was all just the people I knew from 20 to 30 years ago... now all approaching retirement age, or well into that grey hair state.
I thought it was just an off day, and I asked about it, asking if this was the whole congregation or if everyone else was off sick. The reply: "No, this is everyone, and isn't it nice to see all the old friends you know?" They totally gloss over the fact that after putting in 40 to 60 years of preaching to people in the area, there has been no significant increase in numbers - in fact there is a noticeable decrease.... I'd say realistically it's half what there was 20+ years ago. No one there notices though... they just go through the ritualistic motions.