Yes, I was an accounts servant for YEARS!
It was indeed true in my congs, that the majority of funds came from the elderly. (I know that it is all anonymous, but as accounts servant, you get a feel for the patterns of donations, and have an eye on the boxes most of the time)
Also, it was NOT those who had a good income stream that donated much! It honestly came from those with very little means! (As a witness, I found that in line with Jesus Widows Mite illustration, and thought it nice. NOW I see just how warped that is!)
Also, we were in a reasonably affluent area. Yet the monthly donations were pitiful! I even raised it with a CO once as I was concerned that this may be an indication that Jehovah wasn't blessing us as much! He said it was a common thing in our district!
Then the money grab thing from Bethel happened, where the Society "requested" all the funds in each cong bank account be sent to them, and we could keep just $5000 (how NICE of them!) Our elders told me to IGNORE that request, and they kept over $15000! I raised it and said that they were going against "theocratic direction", and they came up with excuse after excuse to keep the funds! Contrary to what Bethel told each cong!