I deleted my original response☺
I don't think there's a way. Whatever you have in the list or the found set for graph will be plotted. I guess you could try removing the 0 and leave the value as blank, but I don't think that will work. Each point is a list row or record in the found set.
Not possible with the native chart object in FileMaker.
But there are other options if you research plug ins or charting in a web viewer. Maybe one of those approaches could do this.