So I have snapshot data added to the data model at the end of each month.

And my data is very similar to the below illustration.

Each item will have its unique item code, and I would like to compare the current month list against last months list to see if there is anything that cannot be found in last month's list. If yes, then consider it as a newly added item and show in the Column [Newly Added].

ReportDate    Item  NewlyAdded

31/1/2021     001    No  

31/1/2021     002    No  

28/2/2021     001    No  

28/2/2021     002    No  

28/2/2021     003    Yes

31/3/2021     001    No  

31/3/2021     002    No  

31/3/2021     003    No  

31/3/2021     004    Yes

Anyone has ideas how to do it in Power Query?

Thanks in advance