I teach many students. Therefore I want to say that I made written tests and gave test scores and graded those students attitude also. Should I write student's to mean I graded each student or students' to mean I graded all of my students?

Tks

I teach many students. Therefore I want to say that I made written tests and gave test scores and graded those students attitude also. Should I write student's to mean I graded each student or students' to mean I graded all of my students?

Tks