Piechart in a loop

I give a collection of beans with Java to my Report. Every bean has a list with an object. 
I give this list with object  as a datasource for a table where the values are shows. This works perfectly as expected. 
However when I give the same list as a datasource to a Pie Graph all the pie graphs show the values of the last bean in my collection. 

How is it possible to do this correctly?