Subtract the current row with the previous row

[sam_gift]

Hi I have a below requirement.

I have a table named forcast table with forecast version and values.

I need to initially calculate the sum of values for each forecast. and subtract the forecast from the previous row(for 2022.7: I need to take 2022.8 and subtract 2022.7, for 2022.8: I need to take 2022.9 and subtract 2022.8 and so on)

Atlast, I have to build a graph with the differences. Please find the clear requirement in below link

 

[lbendlin]

Please provide sanitized sample data that fully covers your issue.
https://community.powerbi.com/t5/Community-Blog/How-to-provide-sample-data-in-the-Power-BI-Forum/ba-...
Please show the expected outcome based on the sample data you provided.

https://community.powerbi.com/t5/Desktop/How-to-Get-Your-Question-Answered-Quickly/m-p/1447523