Heya,
There are a couple of things you have to keep in mind and this is important in every analysis:
1. have a dedicated Date table - your file was missing such table so I created one for you and connected it to your Billing Date
2. formatting is key - your Percentage column is not formatted properly and unfortunately there was nothing I could do since I didn't have access to the source file
3. create explicit measures - do not rely on PowerBI to do the Sum or Count for you but specifically create these measures
Having said that, if I understood your problem correctly, I believe it can be solved by creating a calculation group with two simple measures (as below):
YTD = CALCULATE(SELECTEDMEASURE(),DATESYTD('Date'[Date]))
pYTD = CALCULATE(SELECTEDMEASURE(),PARALLELPERIOD('Date'[Date],-1,YEAR))
See attached file.
If the post helped then please give it a Kudos and mark it as the solution so others can see it.
Cheers,
