Looks like you are loading Purchased & Registered separately in your script - if you rename the Year field in both, to the same thing, Qlik will join the two tables.
You can then drop your (new) Year field as the dimension and add Count(PurchasedID) and Count(RegisteredID) as your measures - use a Combo Chart, so you can add more than one measure.
Thanks for the response Andrew.
My bad, probably i didn't explain clearly in my original post.
Basically, i have an RegistrationID which has PurchasedDate and RegisteredDate fields against.
So, to get the count of Purchased Products in a year i do (Count(RegistrationID) ,Year(PurchasedDate))
The same way for Registered Products (Count(RegistrationID), Year(RegisteredDate)).
still possible, although a little changed:
Year(RegistrationDate) AS Year,
Year(PurchasedDate) AS Year,
RegistrationID AS PurchasedID
DROP TABLE SourceTable;