I would guess way more than half are still working.  I can probably get some data on that if you like.  The main problem (no offense intended I just don't think it is accurate) I have with your original statement is that "few are eligible" when it is a very high number.  It also amount to billions in liability.  The projected unfunded amount is something near 10 billion at this point I believe.  This is because the early Tier systems did not set aside enough money to cover the costs we are now seeing.  Primarily because of lifetime medical guarantee and the high cost of that.