In the manual you see the Histographpage with a list to the right with the highest ranked cities of the world. In my Histographpage I cant see that. I can choose between power, point and cultural, and to the right I se a list over the civpoints.
I wouldn't put too much stock in the games assessment of which are the top cities in the world. I am not sure what this is based on, but I often see size twelve capitals of third-world civs with no wonders ahead of size twenty capitals of the most advanced civs with three wonders. This assessment is about as accurate as those made by the military advisor, whom I absolutely do not trust to advise me.