i am trying to create a radar chart.my apex class is

public class Sample {
    List<String> xx = new List<String> {'Value Proposition','Business Understanding','Responsiveness','Terms & Conditions','Quality','Customer Care','Strategy Alignment','Relationship'};
    public List<RadarWedgeData> getData(){
          List<RadarWedgeData> pie = new List<RadarWedgeData>();
           for(Integer i=0;i<xx.size(); i++)
             pie.add(new RadarWedgeData(xx.get(i),1,2,3));              
       return pie;
    }
    
// Wrapper class
public class RadarWedgeData {
public String name { get; set; }
public Integer data1 { get; set; }
public Integer data2 { get; set; }
public Integer data3 { get; set; }
public RadarWedgeData(String name, Integer data1 , Integer data2,Integer data3) {
this.name = name;
this.data1 = data1;
this.data2 = data2;
this.data3 = data3;
}
}
}

and my visualforce page source code is

<apex:page controller="Sample">
<apex:chart height="600" width="700" legend="true" data="{!data}" >
<apex:axis type="Radial" position="radial" fields="data1">
<apex:chartLabel ></apex:chartLabel>
</apex:axis>

 <apex:radarSeries xField="name" yField="data1" tips="true" opacity="0.4"/>

  <apex:radarSeries xField="name" yField="data2" tips="true" opacity="0.4"/>
<apex:radarSeries xField="name" yField="data3" tips="true"
markerType="cross" strokeWidth="2" strokeColor="#f33" opacity="0.4"/>
</apex:chart>
</apex:page>

but my chart is not rendering labels properly.its cutting Value Proposition label,Strategy ALignment as you can see in following link https://www.dropbox.com/s/95olcjztxgg7i2r/labels%20not%20rendering.png .please guideline how to render labels properly.Thanks