1996 was the date that the New Living Translation was originally published.
2004 was the date that the second edition of the New Living Translation was published. You can read about the improvements made in this transition here.
Since the second edition was published in 2004, various queries have been submitted related to details of the NLT text. (Queries are constantly being made of Bible translations, especially the newer ones.) Most of these queries came from our own editors as they worked on new NLT commentaries and Bible notes, closely comparing the NLT to the original language texts. The 2007 changes were mostly minor textual or footnote changes. You can view these changes here (link to PDF of chart). The edits demonstrate the NLT Bible Translation Committee’s continued commitment to both scholarly precision and clear communication in modern English.