While the obvious explanation is that the faculty of this university are remarkable in every way, cynics may suspect that the rankings authors input an incorrectly low faculty number, which would explain both our extraordinarily high citations/faculty and our extraordinarily low staff/student ratio.
In any case, at least for showing progress, U of C has done remarkably. In 2006, it ranked 266. In 2007, 166. In 2008, 170. In 2009, 149.