Is it normal/ethical for student grades to be assigned according to quotas? In my undergraduate Physics courses, I have heard from my Professor last semester that he got in trouble from the physics department for passing too many students.

This semester, the TA in the lab portion of my class (who grades our lab reports) came flapping around a memo he got, also from the Physics department, stating that the average grade needed to be 75% and he will now be grading accordingly, after a few weeks of normal grading.

I typically spend up to 4-5 hours on these reports, typing up formulas and doing analysis, calculations, etc. I have gotten a 100 on every lab report in my first semester and up to that point in the second. Now, after the ultimatum, I'm losing points for things I didn't before, and being asked for additional analysis that has never been required. I already spend as much time as I can, and this harsh grading feels out of nowhere and undeserved.

Questions:


Is this normal that teachers have quotas?
Should it affect students who actually put in the work?
Does this seem like an ethical issue of arbitrary grading that I should bring up to the department or my professor?
Unfortunately, the universities and colleges are run by managers and not only by academics. In ideal world, all students' work should be marked according to its merit; for example, if all mathematical problems are solved correctly, then the paper deserves 100%. Academics usually understand and share this view (apart of a few strongly believing that "no work ever deserves 100%"). 

Unfortunately, people who manage universities, are not always guided by common sense or mathematical reasoning. They seem to invent some obscure metrics and force them on the rest of academic staff. Academics do not think it is correct, but they have to play by the rules which are set by non-academics. 

Unfortunately, students become a collateral damage in a clash of two cultures: academic and management. If you want to query this, best ask not your professor, but a Dean (anonymously or as a part of larger group). The misguided policies arrive from the very top; your professor has not much power against it.