Here's what Payscale.com says about the list:
Only employees who possess a Bachelor's Degree and no higher degrees are included. This means Bachelor graduates who go on to earn a Master's degree, MBA, MD, JD, PhD, or other advanced degree are not included.In case you don't see your college major in the graph, the full list can be found here.
For some Liberal Arts, Ivy League, and highly selective schools, graduates with degrees higher than a bachelor's degree can represent a significant fraction of all graduates.
Careers that require advanced degrees, such as law or medicine, are not included.
For students who major in physics, I highly recommend a minor in computer science. For students who major in mathematics or statistics, I highly recommend a minor in either computer science or finance. Having an applied skill that complements your "pure" math or science major will give you far better employment opportunities after graduation.
As I've said before on this blog, I think a technical bachelor's degree (e.g. engineering or computer science) combined with an M.B.A. makes a powerful combination that will result in a very high salary. An M.B.A. is also a good follow-up to a degree in economics, finance, accounting, marketing, or information systems.
Previously, I have blogged about average starting salary by category of college major and about median earnings by level of education.