What is total number of PhDs globally? How many graduate each year? I am interested in long-term dynamics of the number of PhDs, having recently received a PhD myself. So far, I have only been able to find bits and pieces, mostly pertaining to USA (see e.g. here, which says that there are roughly 40k PhDs awarded annually in the United States).

Any input is appreciated.
In this document you can find some data for Europe and Asia. In particular, it appears that [linked document, p. 47]:


  In 2010 an estimated 125,000 doctoral degrees were awarded in the EU alone (out of a population of 500 million), compared to 70,000 in the US (with a population of 300 million) and 16,000 in Japan (with a population of 130 million). 


Probably from the EUROSTAT portal you can find other data for Europe.