The American Association of Neurologists surveyed the neurologist
community in 2000, and came up with the following:
--There are 13,5000 practicing neurologists in the US.
--The mean age of this group is 47 years old.
You can see a reference to these data here:
What are the demographics of neurologists in the United States?
along with additional details for the demographics of the neurologist community.
It is not likely that the overall size of the neurologist community
has changed significantly since the 2000 survey, as new practicioners
have replaced those that retire or otherwise leave the community.
Since a few years have passed, the mean age has shifted upwards, and
is now likely to be quite close to 50 years of age, or perhaps a few
Hence, there are currently 13,500 neurologists practicing in the US.
About 50% of the neurologist community -- or 6,750 practicing
neurologists -- are under the age of 50.
I trust this is the information you are seeking.
However, please do not rate this answer until you have everything you
need. If there's something else I can do for you, just post a Request
for Clarification, and I'm at your service.
search strategy -- Google search on: ["1000..100000 neurologists" age OR years ]