Visifire charts AxisLabels FontSize

<charts:Chart.AxesX>
    <charts:Axis   LineThickness="0.25" >
        <charts:Axis.AxisLabels>
            <charts:AxisLabels FontSize="20"></charts:AxisLabels>
        </charts:Axis.AxisLabels>
    </charts:Axis>
    
</charts:Chart.AxesX>