"jews" and doctor's degrees

[Qumran]

In one of Daryl Bradford Smiths recent broadcasts (maybe Friday 19th June 09 with Ken Palmerton) Smith says that out of 14.000 that takes a doctor's degree in medicine 12.000 are "jews". Ken Palmerton (?) then replies that when it comes to dentists the proportion of "jews" is even higher. Anyone who knows more about this? What could be the information source?