[otrs] Open + Close + Ticket Statistics

Hello, I´ve been trying otrs for a couple of days now, but I haven´t been able to figure this out, tickets keep gaining age, and on the statistics module there´s no way of knowing for sure the time that it took for the ticket to get close (wich should be the diff from the opened time to close time minus the hold as far as I understand). Is something that I´m missing or is it just not there? Regards.