How to force spacing between fusioncharts stacked bars?

I'm currently displaying a fusioncharts stacked bar chart vertically and i have a problem with bars labels that are superimposed on each other :

Is there a way to force margin or global spacing between each stacked bar ?

PS : I don't want to use plotSpacePercentthat just reduce the size of a bar and don't solve the superimposed label problem

i didn't found any solution to set spacing or margin betwwen stacked bars, but we can force visible plot number we want to see on screen.
So if we reduce visible plot number, we have more space between bars

Solution :

chart: {
  numVisiblePlot: 3
}