Issues with my lease/ RS

[RCyanks]

So I've been having some issues with the new landlord. First he didn't wanted to fix some problems with the building (rent stabilized). He bought it with the problems... Then after going Through The city, they fixed most of the problems, now they're trying to buy Everybody out to rebuild the building but no one is moving.

So now they're trying to increase the rent from 4 or 5 years back (my lease hasn't been renewed since 2007) adding what they were supposed to raise every year... Until 2011. Is this legal?