I just searched pgp.mit.edu and it looks like the first key I have on there is from 1998[1] (with several others from previous jobs, although I don't know why I had two keys when I worked at BBN).

I don't think I even have a key for my current email address.

[1] http://pgp.mit.edu:11371/pks/lookup?op=vindex&search=0x867C6...