Contribution of Growth Formula

Question

The question I am trying to answer is:

Which store contributed ($\%$) most to the "National Share of Sales Growth" $(14,14\%)$. I would like the formula to calculate the "contribution of growth" of each store? Which store is "Pulling up" the growth rate $(14,14\%)$ and which store is "Pulling Down."

I would like to answer this question like: Store 1 contributed most the national Share of Sales growth by xx%

Can Someone help me with this?

1. Share of Sales Formula: (Subscription Sales/Total Sales)
2. Growth in Share of Sales: (Current Year Share of Sales minus Prior Year Share of Sales) / Prior Year Share of Sales

Answer 1

Multiply the average share by the number of participants (three in this case).

Divide a share by this value to get the percent contribution.

So $3\times14.14=42.42$, and so the percentages are $14.58/42.42=34.4$, $7.66/42.42=18.1$ and $20.47/42.42=48.3$.