328 production by color?

Does anyone have access to production records indicating the number of 328s produced in each of the available color? The reason I ask is that people keep telling me that my 328's 506/C Blu Medio Metallico is quite rare, and my father just reported that of the 25-30 328s at the Concorso Italiano, none were Blu Medio.

Being the research guy I am, I'd love to see statistics on numbers in each color to see just how rare Blu Medio is (and other colors are.) I'd imagine that other colors, like Oro Chiaro, Prugn and Azzurro are rarer.

Thanks!
Sam