Help with sum to work out a yearly percentage.

[Nickvii]

I'm having a trouble trying to work out a percentage growth.
basically, I have 14 cells in one row.
Jan to Dec- Total - Growth Percent.
I want to work the yearly growth of this row.
Example

Jan £10
Feb £10.50
March £11.20
April £14.20
May £13.60
June £12.30
July £13.60
August £13.95
Sept £14.20
Oct £13.99
Nov £12.99
Dec £14.60
Total £129.23
Yearly Crease % - this is the cell I can't figure out what excel sum in to work it out.

Any one able to help? So that every month I add a new figure like above it calculates the %.
Its prob really simple but I'm stumped

 

[Andrew Poulsom]

Growth using what as a starting figure?

 

[Nickvii]

Hi Andrew, sorry January

 

[Andrew Poulsom]

Maybe:

=((B13/12)/B1)-1

 

[Nickvii]

Let me explain a little more. It will always use jan as the base figure.
What I am doing is creating a dashboard for my contracts stock take.

 

[Andrew Poulsom]

How about?

=((SUM(B$1:B12)/ROWS(B$1:B12))/B$1)-1