I am trying to create an auto expanding pie chart.

I have a list of data which is added to every day. It is used to log new
suppliers. Each supplier is assigned a commodity. I have defined a wb range
(CG) which looks at one column of the data (Commodity) There are 8 different
commodity that the user can choose from. I would like the pie chart to show
the percentage of new vendors by each commodity. At present I am doing this
with a helper table which counts the number of occurances and then I base my
chart on this.

Does anyone know of a way I can do this without a helper table?

TIA