How to change scroll interval of speed timer?

How do I change the scroll interval of the speed timer graph? It says "Speed Timer (1s)". Right-clicking the graph doesn't bring up any menus, I couldn't find the option in the configuration dialog, and I didn't find anything in the knowledge base either.

Thanks!

It is currently not possible to change the interval.

Oh, no wonder I couldn't figure it out. Thanks for your reply!