I am working on a sales spreadsheet and I need to take each month and find
the average increase or decrease in sales but using a %.

Example of spreadsheet:
January Sales
Current Sales Renewal Sales Difference
$4,162 $4,132 ($30)
$770 $663 ($107)
$4,932 $4,795 ($137)

I need to take the difference column and get an average % of either positive
or negative with the max of 100%

I hope I explained right - been working on it for awhile & now brain is
fried... :)

Thanks for all help!!!