National Security Archive senior fellow Jeffrey Richelson first reviewed the history in 2002, but all mentions of Area 51 had been redacted. So he requested the history again in 2005, hoping for more information, and sure enough, he received a version a few weeks ago with the mentions of Area 51 restored.
http://www.azcentral.com/news/free/20130816cia-acknowledges-area-not-ufos-aliens.html