That the client knows it is being used for a period longer than 10 years, but late last year, a new extension has been changed. Make a new extension, I don't know.
Which is the number that the client knows best. It was used for a period longer than 10 years. But at the end of last year, a number of new changes. I made a number of new customers
This is the number that customers know. It was used for a much longer period of time 10 years. But at the end of last year, have changed the new number. Make customers don't know the new number.