Firstly, sorry if my english is bad, I'm french !

So, I have a script that executes reached a certain level of scroll in the page. This script is a number counter which starts when the scroll makes it visible (In the middle of a onepage website).
However I do not know how to make this script will run once. 

So when I get to the section containing the counter , this one begins to reach a specific number . But when I scroll again , the counter restarts from 0.
I think I have find the loop, but my knowledge in Js is not good enough to modify it... Can you help me please ?

Thank you !