This foolowing screenshot shows that I have 1 opened and 3 closed tickets for this client/user and it shows 4 as a total number of tickets

To check how many of them are opened I need to click on the total number in order to pop up the information.

I would like to change this behavior.
I meant I would like to change the standard behavior of showin total number of tickets (from this client/user) to somethink like this:

[ #opened / #total ]

I need some information to get started.
Which function is responsible for the counting #opened and which for counting #total ?