Yearly salaries vary in any industry depending on education and experience. You may have a PhD but only have a year of experience and make less than someone with a Masters and 10 years experience. The higher the education usually means the high salary. Their salary also depends on where they live. If teachers/professors are in high demand where they live, they will earn more. For the median
. annual salary for professors by city go to http://www.payscale.com/research/US/Job=Professor%2c_Postsecondary_%2f_Higher_Education/Salary/by_City