The Dept. of Education recently published the most detailed data I have seen on earnings by major at each institution, as well as debt levels at graduation, etc. Links are below.
This info ought to come with some caveats. For example, the salary numbers are for the first year after graduation, so I assume a lot of the Chemistry, Biology, etc. majors were in medical school. Graduates who were still in school weren't included in the "average" calculation, but it seems to me that most kids who get, e.g., a Neurobiology degree likely expect to go to medical or grad school (maybe a few are working for a couple of years first?). Also, there are several studies out there that suggest those with liberal arts degrees catch up with, and even pass, engineers' and STEM majors' salaries over time. (I was an English major. Worked for two years, then went to law school. My earnings in year one post-college were ok, but not as high as if I had chosen some other majors. By year six, when I was working as a lawyer, the picture looked different.) Even so, these are some of the best data I have seen on this subject.
Dept of Ed College Scorecard: https://collegescorecard.ed.gov/