So I’m trying to measure the sales growth of specific salesman. Any salesman has the highest sales growth (min $4\%$) will receive a giftcard.
However I found it not fair to compare when a saleman doesn’t sell a lot last year, for example $\$30$ and this year sells $\$4000$, which is $(4000-300)/30 = 1233\%$ growth. Meanwhile many salesmen have sales of $\$10,000$ last year and this year $\$10,040$ means they improve only $0.4\%$, but overall, the volume is much more higher. Is there a way to calculate so it can feel more right?
Two ways out:
Set the minimal amount for sales in each of the two years: i.e., only those who sold at least $\$2000$ in each year are eligible for the prize. Then compare their percentages.
Have two prizes: one for the highest volume of sales over two years, and one for the highest rate of growth. These are different kinds of achievements, so comparing one against the other would not be natural anyway.