I'm assuming the attendance is less strong than Madrid and Rome. Hamburg used to be the unpopular little sibling of the clay trio, and Monte Carlo has clearly inherited the title.
Madrid is getting the Indian Wells super 1000 treatment, right? So that isn't going anywhere, nor should it with the relatively constant success of Spanish players in both the mens and womens game, and Rome has even more prestige and history than Monte Carlo does so that's safe too.