Need to know the Customer which has not yet made any Transcation

Hi experts

Am having around 25000 Customers in my System,

in which only some are Active and having transaction

now i need to clean up my system, for that i need a query, which shows me

the List of Customers who has not yet done any transactions till now so that i can remove it from the system

Am using sap 9.1 Version

Regards