What are the standard workloads for mathematics TAs at state and private universities in the US? I am an international student, and now pursuing my Ph.D in pure Math in a not very good (ranking 70+) and relatively small state university in U.S.
As usual, I am a supported TA, and I am wondering whether the teaching load here is too heavy.
The department supports about 50 TAs in total. There are two types of TA here. For those who have not passed the Speak Test (which is another awful thing), they can only serve as graders, and are expected to work 12 hours in grading hws per week. For those who passed the Speak Test, they have to teach 3 or 4 sessions of recitation every semester.
Based on my experience, I feel so tired after a whole week's work as TA that I have little time or energy to do research. And I once heard that in some (private) universities, a typical TA job consists only teaching two recitations per academic year...
My questions are the following. (To be precise, I only care about a TA duty in math major.)

What does a typical TA duty (especially the working hours) look like in a state university and in a private university? Especially, is it true that a TA in a state university usually works longer in his/her TA duty than the one in the private university?

Is the TA duty here reasonable compared with other state universities?
Not sure if this data point is really deserving of being an answer, but:

I graduated from a top-25 math department at a fairly large state university 5 years ago.  The standard TA assignment was 4 lower-division recitations (e.g. calculus) per semester.  Our contract permitted us to be assigned up to 20 hours of teaching duties per week, though most weeks the assigned duties took significantly fewer hours.  Students working as TAs for advanced courses (upper-division or graduate) were usually assigned 2 recitations, but were also expected to grade homework, etc.  

So what you describe doesn't sound totally out of line, unless you are spending considerably more hours per recitation.