lookup

Hi
I have two tables that list customers by account number order and the limit of their account. What I would like to do is compare month to month so I can see if we have increased or decreased any account limits, added any new customers and their limits or removed any customers and their limits
Column "U" I have a formula that returns if the customer held an account with us the month before, in column "V" I would like the difference between this months and last months Overdraft limit. Unfortunately I cant just minus one from the other as the rows can change from month to month as new accounts are added and old accounts leave. (example shows this)