Calculate GDP using Asp.Net (c#)

Hi:
   I have the following task.

1)Claculating  the current GDP of Countries

GDP means Gross domestic product (GDP) or Gross domestic income (GDI) measures of national income and output .Plz refer the following link:

"http://en.wikipedia.org/wiki/Gross_domestic_product"

Is there any third party tool or webservice  is available to use in .Net.Can any one sendme suggestionor code.

Thanks