Storage Design Analysis Manager

I have a question about the storage design wizard in the analysis manager.

We are working with different seasons in our reports and every week we update the data of the seasons in our cubes. But as seasons end, and at some point the data for old seasons doesn't change anymore, I don't think it is necessary to update every season every week (which we now still do now for seasons in, for example, 2004). It's a waste of time. So my question now is. How can I storage the data of previous seasons (and work with them in the report) and still be able to update the current season? Can I use the storage design for this??

Did you look at cube partition?

Well I just tried this... but its not working, but maybe I'm doing something wrong. I understand that with the partition you can make slices of differents seasons. But when I process my cubes (witht the option "process all cubes"), the first thing it does, deleten all the data in the cubes. And this is what I don't want. What I want is to update only the current season and to keep the rest of the data in the cube????