MLB baseball team managers.
Possessor of my soul.
I feel so bad misreading it as Master Chief 
If you add to this number the enormous number of people with “engineer” in their job title who never received an eingeering degree, the percentage would possible be just 1-2%. It’s difficult to find good numbers.
I believe I’ve read somewhere that there are fewer than 100 certified forensic anthropologists in the US. I don’t know if that means there are other people working specifically in forensic anthropology as opposed to medical examiners and archaeologists and such who work with bones in a more minor way.
Does soldier count ?
There are millions of 'em, but only a couple of generals. That’s probably the profession with the smallest percentage of “top-certified” people.
(political commentary ahead: yes, I know that soldiers are professionals, with a lot of certificates. And god bless 'em for doing a good job. But I’m not sure it’s the type of job certification that the OP was asking about.)
It’s an attempt to deal with the volume - but it’s a failed attempt - which means these smart HR people did not analyze the problem and identify the true predictors of a good tech hire.
In tech, certs are pretty much useless. They don’t actually identify the qualities that make a good tech person - and those qualities are primarily, smart, ability to learn (on your own with little guidance) and flexible problem solving.
I can’t speak to Cisco, but FWIW Microsoft also has more stringent levels of certification such as Microsoft Certified Master and Microsoft Certified Architect. I haven’t gone through the training, but I occasionally have need to chat with MCMs (I’m in one of the product groups at MSFT) and they’re pretty sharp folks. There are few enough of them that I think all of them are listed on a single web page.
http://www.microsoft.com/learning/en/us/certification/master.aspx
Interesting thought, but I’m not exactly seeing ranks as the same as a certification. Certainly, ranks can be considered different to job position, so you can have someone with the rank of Colonel whose job in the Army is Principal (what word would be better) of a Basic Training program. Another Colonel could be captain of a bomber.
And, I don’t think you get a large degree of leeway with regards to when you apply for “certification” at the highest rank, as it’s at least in part driven by the needs of the military - you can’t just promote everyone to General just because they “have what it takes” - you promote until you don’t need or can’t afford any more Generals.
E.g. can I, a civilian, show up at the nearest Navy base and say I want to take the Chief Petty Officer certification exam, so that if I ever decide to enlist, I would start as a Chief Petty Officer? I highly doubt it - it doesn’t work like that.
certain medical specializations? just like that epstein guy you often read about at reader’s digest (before.) my friend who’s now retired said he was the only qualified child neurologist in the manhattan area.
Certifications for programmers are eminently useful for subject knowledge. I absolutely use them when I’m hiring contractors; I have zero interest in training a contractor, who might otherwise by an astounding developer, in the technology I need them to use. Even when hiring a full-time developer, it can make the difference between two otherwise equally appropriate candidates.
That’s fascinating. I personally know 5 people that I know for a fact have a BS in engineering (I say it that because I may know more that I don’t know about - if you follow). 4 of the 5 are PEs.
Reply to Cerowyn, glad that works out for you. It never has for me. In my experience, certs are a completly UNreliable indicator of performance. For example, I’ve twice been hired to mentor new PMOs filled with PMPs. I don’t have one, but I’ve got a metric boatload of successful project management experience.
My board certified feline specialist veterinarian estimates this at about 80.