I just completed my 3rd RUSA cup, which warranted firing up Excel and having fun with some numbers.
Since the award's inception in 2003, there have been 457 RUSA cups earned and applied for among 261 riders, so that breaks down to 42.8% of cup earners going on to earn at least a 2nd cup! That led me down the path of wanting to know what percentile my 3-cup earnings have put me into compared to those who've also earned one.
Looking at the counts, we can see that a majority are 1-time cup earners, but the repeat offenders aren't uncommon.
The interesting point is those greater than 10 who've earned an Ultra-RUSA cup, of which there are only 3 individuals. That single datum at 20 RUSA cups is a Texas-shaped outlier whose identity I'll let you guess, who's earned a 2nd ultra.

So my 3rd cup puts me among the top 27.6% of RUSA cup earners in the 72.4th percentile. It will probably be 2028 before I will have a chance to work toward #4.

Looking at cups earned/claimed per year, I see a pretty similar shape to my analysis on R12 and KHounds, with a peak around 2015/2016 reflective of RUSA's membership zenith. I'm going to guess the "every 2-year" peak pattern is an artifact of the cups not overlapping (only every 2 years if you're stretching it out) and the relative sparsity of the 1000k needed to earn the cup. Interestingly, there is a bit of a pattern of the PBP year being down (maybe because only "Once a Year 1200k" folks like me are going to PBP, which doesn't count?)
Finally, 261 riders over 23 years is not a lot compared to the number of active riders who've signed up for and ridden with RUSA. The cup is HARD to earn, requiring one of everything <=2 years, which requires a great deal of preparation, planning, luck (or an ungodly amount of schedule flexibility!) I've had at least one fall through due to schedule constraints on my part, making that last event hard to get.
What does it all mean? IDK, probably that I have too much time and am very bored while stuck in a meeting that should have been an email.
The cup is an epic trinket, being the only one from RUSA that you can drink out of. You do tend to get weird looks if you use it for morning coffee for a month, as I did at my office when I earned my first back in 2019. Congrats to anyone who's ever earned it.
Josh