Statistic Usage

[nandozzi]

Hi all,
i have a simple question but i haven't any idea how to do it. I want to do a graph based on the Average Solution. I want to see the trend of the resolution time in a specific time range. I have used these parameters, but it seems there is anything wrong. Can you help me?

X-Axis= Create Time:
Scale: 1 day(s) month(s)
Between: 01-01-2009 - 12-31-2012

Value Series= TicketFreeText

Restriction= Evaluation by: Solution Average

Thanks in advance

[nandozzi]

Please anyone can help me?
I need only to do a graph like this one: