Active tickets report

Hi, I am having some problems with historical active tickets. 1 - the current active ticket report - if i ran this report for last week it will only tell me ticket that are active for last week. If I have some aged tickets, older than last week, they will not show up on the report. 2 - I also need to be able to report on how many active tickets i had at any given time. Say this week we have x amount of tickets active, now i want to know how many active tickets I had open this time last year. Any help will be appreciated.