plate question

After looking at the ILS-Z approach in NC that was discussed here some time
ago, I was curious how many similar approaches there are, and if they all
are military. Thanks to the uniform naming NACO uses for its chart files,
it was fairly easy to get a list of all the ILS-Z approaches: there aren't
that many, probably a dozen, and all of them are military -- usually there
would be two -- a Z GPS approach, and a Y RNAV counterpart.
But for one place:
http://www.naco.faa.gov/d-tpp/0610/00641IY12.PDF
There's only ILS-Y approach here, and no Z approach. Does anyone know
why there's no Z?


Andrey