In a research paper, I want to use population size (count) as an adjective for population. Here the population size is 60, i.e. there were 60 individuals in the statistical population. Is it OK to say
In a 60-people population...
Or should it be reworded as:
In a 60-individual population...
I am not sure if either of the above sentences are correct, but I tried to follow the grammatical convention used, for example, in a 100-dollar note, a one-step program, a two hundred-page book, a ten-minute workout,etc.
Which style should I use to make a modifier that, when brought before "population", says that the population consists of 60 people.
Some context for further clarification:
Sadeghian et al (2009) examined the relationship between organizational self-esteem, organizational feedback, and personality types in a 60-[people/person/individual?] population from among education employees of Jarghooyeh Sofla (a county in Isfahan).