How to show round off values in chart in asp.net

I have a column in gridview which displays float values. But while the same value in chart I need to round off to nearest whole number and display it in chart.

i.e if it is 12.6745 then it should be 13  

<asp:Series IsValueShownAsLabel="True" Legend="Legend1" Name="(%)"   
XValueMember="Test" YValueMembers="PERCENT">          
</asp:Series