Who has left the NIC?
 

I'm looking for groups which have left the NIC over the last 25 years and haven't returned:

I believe that this is true of
Kappa Sigma (FLA, but didn't come back, right?)
Phi Delta Theta (FLA, but didn't come back, right?)
Lambda Chi Alpha (within the last 3 years)
Tau Kappa Epsilon (within the last 3 years)

Are there any other groups? Are any of these wrong?

(I'm trying to make an NIC template on Wikipedia and want to include the "Former" in a separate section. I'm using 25 years, since I don't want to include the groups that aren't part of the NIC due to Mergers, the last one of which I know of is the Phi Sigma Kap/Phi Sig Ep in 1985)