Plastic Model 2008 annual revenue: anyone got figures?

Has anyone got any kind of figures on how much the plastic model hobby that we enjoy generated in US dollars for 2008?  There has to be a statistic somehwere but everythign I have tried to search on the net has resulted in page after page after page of kits for sale and online hobby shops. I'm pretty sharp on searches and usually find what I want, but to no avail this time.

When discussing the hobby with others, especially potential (non hobby related) sponsors for our annual show, it would be helpful to cite the avaialable dollars generated by the hobby with accurate numbers.

 thanks in advance!

David