Increase/Decrease with new data import

Hey,

basically this is not possible right now.

Each time you import data, the Power BI dataset does not reflect the change, instead the imported data represents the complete data.

You can cricumvent this issue if you are on Power BI Premium, because Premium provides the of incremetal data refresh (as far as I know sooner or later this feature will also come to the Pro licensing - but there is no date available when this will happen). But you also need date columns to configure what has to be added to the existing dataset.

The most simple way to calculate change, is to either add new date to the same excel sheet with an additional date column that reflects the week in the year. Or create an Excel workbook for each week, make the date a part of the workbook name, This solution will become slower and slower  over time as the number of Excel workbooks will grow over time. I use this solution throughout some projects, without an issue.

Hopefully this provides you some ideas,

Regards,

Tom