Math: Given weekly average data, how can "most improved" be calculated?

Question

For example, if I manage a team of sales people and I want to determine the top 5 sales people by comparing their first week's average sales ("baseline") to 11 subsequent weekly averages (i.e., 12 weeks total). I'm interested in "most improved" which may or may not be the top sellers. If I were to plot each sale's persons weekly average, I would choose the 5 plot-lines with the steepest "slope".

Thanks!

I should have added that I want to compare the 1st week to _all_ subsequent weeks; I do not want to simply compare the 1st week to the final week.

Answer 1

There are many valid ways to accomplish this--with different results; for example, you could simply compare the first weeks out put to the final weeks output; alternatively, you could compare the first weeks output to the overall average output for the entire 12 weeks.