Multiply by 1000 and round up, to pick out the 3 significant digits. Then divide by 10 to get the percentage.
<cfset a=round(1000*350/1171)/10>
<cfset b=round(1000*450/1171)/10>
<cfset c=round(1000*371/1171)/10>
<cfchart>
<cfchartseries type="Pie" >
<cfchartdata item="CompA" value="#a#">
<cfchartdata item="CompB" value="#b#">
<cfchartdata item="CompC" value="#c#">
</cfchartseries>
</cfchart>
North America
Europe, Middle East and Africa
Asia Pacific