Found this by way of a post at SEW forums named Only 12 out of the 100 retail sites were well optimized. This post links to an article named Making It to Page One, which discusses how pages rank in Google and Yahoo based on a categorization of how well a page is optimized. Here is the chart from the article.
At the bottom of the article it says "Oneupweb finds that only 12 out of the 100 retail sites were well optimized, while 23 were moderately optimized, 29 nominally optimized and 36 had no optimization at all." I find these numbers to be very generous, but that is just an opinion, I have no data.