Even if you got the number 30 what good would that information be to you without knowing what the population size is and in comparison how many there are in other professions and their population sizes.
Following on from the logic I hypothesis that retiring causes T2 diabetes because most of the T2s are retired.
I understand what you are getting at and there may be correlation but that is generally because we sit in from of computers for long hours (far longer than normal 9 to 5) being stressed and eating junk food for boredom, stress, problem solving reasons,....