Petra...it does not matter whether it is OK with me...it needs to be OK with Roger. But, I think you would have to do this for Roger to want to mess with it. So, OK with me. Also...Canie's suggestion on how to do this easily is good.

Also...before you spend a lot of time on this, discuss it with Roger. I don't want you to waste your time, and I do not know how to, nor do I have time to, evaluate predictions.
Chris