I'm a little confused (not an unusual state for me lately)

I just bought 3 bottles of Sazerac 18 which were just received at a local store this week. Didn't really look to close at the time. Looked at the label last night and saw that it said "Distilled 1984 Bottled 2002".

I checked the bottles I purchased when the fall 05 release came out and they are labeled simply "Fall 2005". I checked the one bottle I have that came from the 2004 fall release and it says "Distilled 1984 Bottled 2004" (doesn't quite add up for an 18 year old but that's what it says).

What release are these newly purchased bottles associated with ? I find it are to comprehend that 2002 bottles have been sitting around BT (or the distributers) all this time and just now found their way to retail.