How many now living individuals have a PhD in astrophysics, or by some other definition can be reasonably classified as astronomers? I think Richard Feynman once said that only one in a million is an astronomer, I would think there are many more today.
"The worldwide community of professional astronomers is only about 10,000; most are located in the us (with about 1,000 in the UK and 250 in Australia)." From So You Want to Be an Astronomer by Duncan Forbes.
Another source stated that the number of professional astronomers is about the size of a small town.