how to best represent data

Hi

I have data of total sales for 2011 and 2012 for four products (see attached). I also have sales data for these four products for site 1. What i want to do is design a chart that would show me total sales of 2011, 2012 with breakdown for each product AND then also show the site 1 sale of each product as a percentage of total sales of that product.
If it is a column chart, it will have 2011 and 2012 on Y axis with two bars for each year (total sales and site 1 sales). the total sales bar will be subdivided into four product sales. The site 1 sales bar would also be subdivided into four products, but will show percentage of sales of each product as calculated from the above bar.

Clear as mud I suppose. Any help would be great.

Thanks
NJ007