how long does it take for google to remove old website data?

I have a email, (the one i used to apply for university). If i google that email, it will link to my profile on this stupid forum where I registered over 2 years ago. I don't want the university to see that I was a part of this stupid forum. So, I logged into that forum and choose the option to hide my email. and it no longer shows my email. Now it's been over 2 weeks, and when I google, that website still shows up, except with no email when you click on it, but still shows my profile...

I wonder how long it will take for google to remove that from the list....