I've been searching the web for zip code shapefiles (or equivalents) for years 2000 to 2010, and have only managed to find the following:
which carries the following TIGER/Line releases: 1990 | 2000 | 2000 Urban Area | 2002 | 2004 1st Ed. | 2004 2nd Ed. | 2005 1st Ed. | 2006 2nd Ed.
which carries the following TIGER/Line releases: 2006 2nd Ed. | 2007 | 2008 | 2009 | 2010
These releases contain most of the Zip Code Tabulation Areas that I need. However, the 2002 release in the above link does not appear to contain ZCTAs, and I cannot find releases for years 2001 and 2003. Does anyone have links to TIGER/Line releases for 2001, 2002, and 2003, or links to other sources that contain zip code shapefiles for those years? I've seen some online vendors that have this data available for a fee, but given the project's budget, free sources would be preferable.