[otrs] calculating time

Hello. We need to get the following kind of stats: how much time a ticket spent in state X how much time a ticket spent in state Y. For example: 1) A customer sends a request 2) 1 hour later an agent asks him/her to provide additional info 3) 4 hours after that the customer sends additional info 4) An hour after that the problem is solved , ticket is closed. The report should contain (among other things like ticket #, queue, owner etc.) something like that: State Y (awaiting us) - 2 hours State X (awaiting customer) - 4 hours Is there any possibility to do this? Cheers, Ilya Kornev