ASP:Chart method FilterTopN, How can I also keep "Other" as aggregate value?

Question

I have a pie chart that I'm using to show the top sales per manufacturer. I would like to show the top N manufacturers, and have the remainder show on the chart as "Other". If I do FilterTopN, it displays the chart so Area(manufacturer 1, 2, ..., N) is 100%, rather than showing them as a percent of the total.

So if I have 5 companies: A - $32, B - $30, C - $20, D - $10, E - $8

then if I set the MaxManufacturers to 2, I want to see a pie chart with A covering 32%, B covering 30%, and Other covering 38%.

Is there an easy way to do this with the Chart properties (as opposed to modifying the SQL)?