Being in the waiting is enough to add on a lot of stress in the student's mind who has applied for the institute. The reason I am responding to your query is that it needs to be addressed among the masses.
The waitlist for this year can be expected to reach 60 but no one can put an authenticity stamp on it as this has various layers to it. My personal advice to people who are on the waitlist is to prepare a backup option as well so that they do not have to be disappointed.