That makes it about 80% semi’s and 20% revolvers as of 2015, with a clear direction.
I would caution you about those figures. As Glenn said, its not broken down as to who bought what. AND, its just a number of guns made, that year.
ok, the table had guns made from 86 to 2015, and yes, during those years more semis were made than revolvers.
This does NOT, however directly translate into guns owned by civilian citizens. First, you have to remove (somehow) the guns bought by police & military agencies, add in the guns imported, add in the guns sold by police etc., and finally come up with some kind of number for all those guns still in service since they were first made.
Looking at 2015, we see over 3 to 1 autos over revolvers. What do you think the numbers were for 1915??? I have no idea, but I strongly think its NOT 3 to 1 semi over revolver, and might be quite the reverse.
The point I'm trying to make is that there were a LOT of revolvers made since Colt's 1836 debut of the "revolving pistol", and a huge number of them are still "owned" by people. They may or may not be regularly used, but they are owned. They didn't all go to the scrap forges. Where do you think most of the revolvers the cops sold when they switched over to semi autos went? Most went into the private sector, and I'd venture to say, most of them are still there.
Also, just going by numbers made really doesn't give any information on how many people own them. Some folks only own one. Some of us own dozens or more. I don't see any way to accurately even estimate the number to answer the OP's question.
Best I can do is a SWAG, that's not all that scientific. How many people own revolvers?? A lot. Beyond that, I think any attempt to produce an actual number is just a guess. And, I think your guess is as good as mine.