Using percentage values in pie chart control

Question

Hi all,
I'd like to create a chart control that shows me the percentage of a "State" fields in a Users table, very simple.

For example I have these 2 tables:

Users
IDUser - IDState
1 - 10
2 - 14
3 - 10
4 - 12
5 - 15
6 - 12
...

States
IDState - Description
10 - State10
11 - State11
12 - State12
13 - State13
14 - State14
15 - State15
....

and the chart (a Pie for example) has to shows me the percentage of presence of every State in my Users table, with a caption that show the description of the State.

How can I make this?

Thanks a lot.

Luigi