So I've been trying to wrap my head around calculating this with the data I have available.  Essentially I'm looking to determine how many accounts lapsed from the previous month, as well as how many new accounts have been added.  

I have data that has how much someone spent for the previous month, but if they haven't previously spent there will be no entry for the previous month.   Essentially a new account would be one who didn't spend the previous month.

On the flip side, a lapsed account with have entries for a previous month, but if have lapsed there would no longer be an entry (row in the data).

I'd like to total the number of accounts that didn't spend (have no entry for the previous month).

I'd like to total the number of accounts that spent the previous month, but are no longer spending (have entries in previous months, but no longer have entries being added)

I've attached a workbook with sample data.

Let me know if I need to clarify or provide more info.

Best,

Ethan

Edit:   Here is an example of a chart I would be interested in making using this info as well.   Is this possible in Tableau?