I can only answer partly. I'm not familiar with the non-unionized occupations in those sectors. What I will say is, where there is unionization, all the pay grades are public. They're contained in the collective agreement.
What I don't know is how many unions and companies go through the process you've just described of actually charting out that distribution. What I would also say—although I stand to be corrected—is that pay equity as such doesn't focus on individuals and their salaries; it focuses on job categories. I don't think the kind of distribution you're talking about within a particular job category would be addressed through a pay equity program.