Can I Refine My Keyword List to Highlight Top (15) Keywords?

[BrandLabs]

My client is wondering if I could provide him with a list of his site's 15 Top performing SEO keywords. However, based on the layout of everything I've used here on SEOMoz, I don't believe that's possible. Or, am i incorrect? Can you indeed come up with a list of Top (XX) SEO keywords for a given time period, for a campaign/website?

Thanks ahead of time.

[KeriMorgret]

I'd first get a better definition of "top performing" SEO keywords. The ones that get the most visits? The ones that rank highest? The ones that get the most conversions? The ones that drive the highest-priced sales?