How to count active items by month

I have a requirement to show how many active items there were by month. The issue I have is counting the item in the intermediary months.

In the table there is a created date, completed date and open/closed status

 So for example, if an item was created date was in March 2020 and completed date was in June 2020, Then the item would need to add to the month counts as follows

March   April  May  June

1            1       1       0

Hope this all makes sense