Wei:
  Other people have already replied to your question about which date(s)
to use.  I will address the other question about "or how would your
institution handle it."

Although latest entry cataloging is looked down upon, if you are planning
on just using this record in your institution and not sharing it in a
national database, you might consider latest entry cataloging.  This title
in question has changed back and forth from the original title so many
times that you must really evaluate if you are doing your patrons
(remember them?) a disservice by displaying so many similar, yet different
records with links back and forth, to the apparently, same title.  Making
title added entries with the variations would essentially make this clear
in one bibliographic record.

I am not advocating that all title changes be done as latest entries.
However, in cases such as this one, where the original title appears to
be recurring with occasional "fluctuating" titles, common sense may win
out over strict adhearance to the rules.

One other possible local variation would be to make a 246 in EVERY
separate successive bib record for the ORIGINAL title AND add a date
qualifier to those as well (e.g.

246 10  Estadistica de la ensenanza superior en Espana (1993/94)

for the "in-between" title.  That way, if the patron knows what
approximate years she/he is looking for, it would be obvious which title
to look at, from the title browse screen.

These options may not be CONSER Kosher, but when you are cataloging a long
history of a title, and this is only way that retrospective conversion
differs from cataloging a new title change as it is published and you
receive them, when there is no real indication that the title may change
back to an earlier form of the same thing at a future date and you are
not supposed to "predict" the future.  However with retrospective
conversion, you can see the history of the title at a glance and need to
consider how it will best serve your patrons.

Just my opinons on a Friday.

-- Mitch

  _^_                                                 _^_
( ___ )-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-( ___ )
 |   |                                               |   |
 |   |     Mitch Turitz, Serials Librarian           |   |
 |   |     San Francisco State University Library    |   |
 |   |     Internet: turitz@sfsu.edu                 |   |
 |   |                                               |   |
( ___ )-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-==-=-=-=-=-==-( ___ )
   V                                                   V

  "Outsourcing is a desperate remedy for management failure,
    not the criticism of catalogers." -- Michael Gorman,
       "Crisis in Subject Cataloging and Retrieval"
          June 25, 1995, ALA Conference, Chicago