Not sure if my approach is applicable in your scenario but find it below as reference and stored in attached workbook version 9.3 located in original threat.
Step 1: define a calculated field for each month
a. Januari 2016: if [Date]=#1-1-2016# then [Value] END
b. Februari 2016: if [Date]=#1-2-2016# then [Value] END
Step 2: define delta
delta %: (sum([Februari 2016])-sum([Januari 2016]))/sum([Januari 2016])
Step 3: sort
Sort difference in %.twbx 17.3 KB
many many thanks for you reply. Yes, I think in my simple case this will do exactly what is needed...
as a newbie, I am still needing to remember that I can do conditional calculations - you answer is very straightforward..
Your are welcome. Thanks for the "Badge".
Keep reaching out to the forum when needed on your journey. There are lots of "peaps" willing to help out.
Have a nice one.