value 0 in graphs

[masih]

I was mounting the graphs om my otrs and then I realized these values are the only values who show some datas on X-Axis:
-number
-ticket
-age
-title
-created
- changed
- close time
-queue
-state
-priority
-customer user
-customerID
-first response
-solution time
-first lock
-lock
-state type
-unlock time out

all another datas come whithout value or with 0 as value. what i can do to obtain datas like the total time in hours or minutes that an ticket taked to be solved and the time an ticket has been opened and another things else.

i'm using otrs 3.3.5 and OTRS 6.5