Calculating % increase/decrease using average function

[ccheever2009]

I am trying to find the average of a data set, then subtracting by singular data point and dividing by same data point. Ideally =average (New Value - Old Value) / Old Value = Percent Change. The data is monthly tallies of orders a team has qualified. I am looking to average the past months, to the previous month to show a capacity increase or decrease based off the current average. I have been unsuccessful in building this into one cell. I would preferably not have to build another column/row with finding average then doing average-new/new. Any help greatly appreciated.

 

[jorismoerings]

Hi,

Not sure if i understood you correct but is this what you're looking for:

Book1
	A	B
1	januari	10
2	februari	20
3	maart	12
4	april	32
5	mei	45
6	juni	23
7	juli	67
8	augustus
9	september
10	oktober
11	november
12	december
13
14		26,2%
Sheet1

Cell Formulas
Range	Formula
B14	=(AVERAGE(B1:B7)-AVERAGE(B1:B6))/AVERAGE(B1:B6)