This is an interactive chart showing bachelor's degrees in the United States. Change the options to see the story in your discipline or university, and change the y-axis to suit the ratio you think is most important. Or walk through some example stories:
Why Business majors aren't increasing; Computer Science's Gender Problem; Why the humanities aren't in "crisis"

Made by Ben Schmidt, 2013 using D3
For some write up on what these trends might show in aggregate, read some of my blog posts about the importance of gender in changing majors.
Source: NCES HEGIS and IPEDS surveys, via NSF's WebCASPAR. I've grouped up their degree categories a bit in the sciences in particular. Remember that divisions between the sciences, social sciences, etc. are fundamentally arbitrary and historically contingent.
If you want a finer grained analysis of just 2011 majors that drills down inside some of these categories, see my treemap of all degrees in 2011. For an alternate view of the overall data that emphasizes changes to the present day, check out my degree baseline cherry-picker.