They're hard to find because they're essentially meaningless. You can find an MS guy with a huge infusion center and an MS guy unhappy in his practice because all he gets are headache referrals and so he works really slow and only sees 8 patients a day, mostly follow-ups. Is the average of these people meaningful?
You'd much rather see the RVU reimbursement $ for specific procedure and visit codes proprietary to a specialty across different regions and center types, and the average volume of RVUs generated for that specialty. Then you could make some degree of inference that would be semi-portable to your estimated situation. Ah, but a diagnostic angio might pay anywhere from $30-65 per RVU depending on the place, and even at one center, the value of that RVU might change based on your overall volume, the degree to which you collaborate across divisions and departments, your seniority in the division, etc.
And then hospitals might devalue traditionally "dense" RVU categories like critical care time, and overvalue outpatient RVUs to try to drive their faculty to see more outpatients to meet demand. And then, huge academic medical centers are going to pay less per RVU because they have huge staffs and compliance offices and people whose job is to inflate US News ratings at their hospital and someone needs to pay for them. And THEN, hospitals in the middle of Wyoming are going to pay extra enticement money on top of RVUs to retain people who add value to their operation through additional referrals, improved community stature, etc.
So, like many questions that seem straightforward, the reason you can't find a satisfactory answer to your question is that averages are pretty meaningless, the standard deviations are very high, and the numbers you really want to see (RVUs) tend to vary quite a bit depending on obvious but also obscure factors.
So yeah, NIR > NCC > MS > Gen Neuro > Peds Neuro, but there is huge overlap between groups, such that you'll find peds neurologists who make more than some MS specialists, and some MS specialists who make more than some NCC docs.