I have read the question Are there any guidelines for labeling axes in plots/graphs? and related answers and they cover the case where the unit is from the International System of Units (SI), but what about when the graph shows information about people?
I am interested in medicine or in psychology where a lot of graph are related to number of people, is there any wide adopted guideline?
What is the right word to use?
People?
Person?
Individual?
For example if person were a unit of measurement I should write 10 person and not 10 persons because for SI units we do not use plural forms.
In the same way, in a axis label I should write person and not number of persons because we usually write meter (if not abbreviated) and not number of meters.
And then, what is the short form for person? I see sometimes pax but as a short form for passenger of an aircraft.