Ours in the Philippines, teaching positions are classified as: instructor 1 to 3; assistant professor 1 to 4; associate professor 1 to 5; and professor 1 to 6. The highest is university professor.
Is the second number in the ratio indicating the number of lecturers in the scientific section? If so, the number required to establish a scientific department of not less than six lecturers, including three less than their rank for an assistant professor in the field of specialization of the scientific department.
If you mean academic ranks, starting the lowest: teaching assistant, assistant lecturer, lecturer, lecturer, senior lecturer, prof.associate, professor then professor emeritus.
This is a good question. In addition to the helpful answers already given, there is a bit more to add.
In addition to the usual rankings (Instructor, Assistant Prof., Associate Prof., Prof.) here in Canada, there is the very important productivity ranking which RG is helpful in quantifying. Administrators as well as colleagues are keenly interested in the work being done (and papers, books, reports) being produced by faculty.
Productivity ranking is not just a statistic describing faculty but also an index of the level of activity of a faculty member.
Actually the same classification criteria for the teaching positions are observed and used in the Iranian universities. However, a teacher can stay much longer than the specified time within each classification.