Purge List and Timer

Hello,

I need to keep a record of my point list and in each iteration I want to add a new point and remove the last item from the old list (steady list length). 

If I use timer, however, the whole list is regenerated (new random numbers).

attached is a file where I am doing what I want using the data recording component, but that means that I am keeping hundreds of unwanted points.

what would be the simplest solution to this?

TNX