Do a gradual archive thusly:
Verify your data file. Backup your original file. Give it a name like YE1999. Archive and condense to December 31 of the FIRST YEAR only. EG. Dec
31 1999.
Verify AGAIN. Backup AGAIN giving that file a name like YE2000. Archive and condense to Dec 31 THE NEXT YEAR only. EG. Dec 31 2000.
Verify AGAIN. Backup AGAIN giving that file a name like YE2001. Archive and condense to Dec 31 2001.
Verify AGAIN. Backup AGAIN giving that file a name like YE2002. Archive and condense to Dec 31 2002.
Verify AGAIN. Backup AGAIN giving that file a name like YE2003. Archive and condense to Dec 31 2003. Verify AGAIN one last time.
IF ANY OF THE VERIFY PROCEDURES FAIL DO NOT PROCEED TO ARCHIVE AND CONDENSE.
LEAVE 2004 ALONE.
The different names for the backedup files is so you can easily find and restore your condensed data from previous years if you want to view transaction details of what has been condensed.