topcount function chart

[Windelen]

Hello,

I hope you guys can help me out here. I'have a data drop down with 'countries' that is connected with
a datadeck. In this datadeck I have placed a pie chart. For the slices of this pie, I have placed all months of the year 2011. the pie chart shows for each month the 'sold volumn'.
But now I want to just see the top 5 months, based on the 'sold volum'.  Could someone explain me in some steps what to do?

big thanks.