Quite simply, the answer is no. There is no set number or percentages of students who need to fall within a particular grade level in any of the composition courses offered here at USF. Your grade is determined solely by your own effort you put into the course.
That being said, achieving a good grade in the course is not easy. Every year the FYC program goes through rigorous assessment to ensure that that the grading between classes and instructors is reliable and accurate. This also means that the curriculum is aimed at a level of difficulty that consistently maintains a C+/B- average among all students.