How many PhD students does a typical STEM professor graduate during their entire career? The discussion on this infogram made me wonder about the number of PhD students that a full research professor successfully graduates in their entire career.  By professor, I mean a full professor, not an associate or exclusively teaching professor or other positions referred to as professor depending on field and location.  Of course, the answer is not a single number, but rather a probability density function that is a function of field, place, time, university, and probably other factors.  To narrow the scope, I formulate the question as:

For selected fields and countries, what are recent figures on the mean and standard deviation (alternatively median and median absolute deviation, in case the distribution is non-Gaussian) for the number of PhD students successfully graduated per professor throughout their entire career?
It depends on the size and staffing needs of their lab. For example, theoretical computer science and mathematics professors may need no lab support at all.  Thus, they are under no pressure to take grad students or post-docs and can choose just the ones that they want.

However, if you are doing work on stem cells, you may need a great deal of lab support. You would want a team of doctoral students and a couple of post-docs at any one time. In order to maintain continuity, you would want to accept at least one doctoral student each year. So if you had a 20 year career, you would have at least 20 students (or 20 - 7 = 13 given that it takes students 7 years to graduate and you don't want to leave students hanging at the end).

You'll need to narrow down what you mean by a "STEM" field in order to get a more precise answer.