Exclude ticket states from stats graph

[bert]

I'd like to know if it is possible to exclude certain ticket states from the graph on the dashboard.

We have certain custom states for use with billing and such that are of the "Closed" type. Thus when an agent moves the ticket to a closed state and our billing department moves it to another closed state it gets counted double in the graph as a closed ticket.

I'd be happy if someone can point me in the right direction.