<a href="http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC1490160&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC1490160&#x2F;</a><p>Apparently ~2.7% as measured by this study in 2005. Surprised I could not find department of labor statistics on the question. I would say that it is very possible that the proportion has increased drastically since 2005: Many of the people who have fled Iraq and Syria since then are skilled professionals including doctors.