Scroll Menu Speed Problem HELP!

I’m trying to get this example to slow down the scroll speed. I thought it was a cool affect, but I’m trying to find some ideas to either slow it down or another example really really similar that may not scroll with the mouse fast. This follows my mouse movement by the x y coordinates from what I can gather. If I have a really steady hand, I can get it to go slow, but its not easy for people that I’ve put in front of it to test.
Any ideas or examples would be greatly appreciated.