I have product level data in one table which has product name, and its bill date i.e. when the product has been purchased.
In other table I have customer level data which has customer's registration date, i.e date on which customer made his first purchase along with his customer_id and his Average bill value (sum of all the bill amount made by that customer divided by total visits he made).
I want the customer movement of those customer who had joining date before the product launch date, who have increased or decreased their Average bill value.
I have solved one part of the problem showing movement of 'High to Low' and 'Low to High' customers, but what I am not able to figure out is how do I remove those customers who have registered after the product launch date. For example- It would not make any sense to show the movement of these customers as the Average bill value of these customer will be 0 before the Product launch date and it will not be a like to like comparison.
I have attached the sample data, which might help in getting a better understanding of the problem statement.