@neweducation, actually, the public research U’s dropped a lot because USNews changed their methodology drastically between when they started ranking and now.
Here’s USNews through the years: http://web.archive.org/web/20070905010206/chronicle.com/stats/usnews/index.php?category=Universities&orgs=&sort=1983
As you can see, UChicago was between 10-15 for long stretches of time, just like I said.