I have various portfolios of sales info which span across a variety of dates e.g portfolio 1 spans Jan 20 - Jan 21, Portfolio 2 spans Jul 20 - July 21 etc.
I want to be able to show this data overlayed on top of each other so that i can closely compare the trend for the lifetime of the portfolios, essentially ignoring the fact the data occurs across different time periods.
Is there a way of doing this e.g. identifying the first month of each portfolio as 1, next month as 2 etc.