What can we learn there? We’re in a long, modest upswing in grades, following a pause after a big run-up in the 60’s:
We can also see there that private schools are worse.
A lot of this seems to be shifting C’s to B’s, and B’s to A’s, but on net this makes it look like a shift from C’s to A’s:
And the spread between humanities and social sciences is getting broader:
At my school, one of the six colleges actually brags that they don’t like to give anything other than A’s and B’s, and that they try to counsel students out of majors in that college if they feel like they'd have to give them something lower. Unfortunately, that college is already regarded as the academically weakest one on campus.