The old CAF had stats at the bottom of the main page. Thus, you can go to the Internet Archive (archive.org) and type in forums.catholic.com to see all the snapshots of the site taken over the years since May 2004.
Prior to the change, I included a table of those stats in a thread I started. But that thread was in the Back Fence, so it didn’t make it over to the new CAF. I did save the table, though. (See the next post for the table…the character limit won’t allow me to include it here.)
I also made a quick comparison between the final stats of the old CAF vs the initial stats of the new CAF right after the transition:
That gives you an idea of how many posts were lost (because of the Back Fence/Clubhouse, Parenting, Help Desk, and Archives categories did not make the transition) as well as how many users were deleted (all users with zero posts who had not logged in within the past 12 months were deleted).
Now, you can find out the current stats at the About page (https://forums.catholic.com/about)
It’s hard to make exact comparisons as the things being tracked aren’t exactly the same in all cases, nor do I know whether they are even counting things the same way.