Welcome to 1922! Welcome to 1922! Welcome to 1922! Welcome to 1922! Welcome to 1922!
In USA, if the work was copyrighted in 1932, it will be publicly available in 95 years (2027). So in 1998 instead of releasing copyrighted works of 1923, it just stayed at 1922.
The period between 1998 and 2018 is a period where no new works will enter the public domain automatically. Guess what guys, it's going to get worse. By 2015 or so the weight of our culture having missed 17 years of public domain works will hurt a lot.
Actually though, it's worse in the music field. Pre-1972 recordings weren't governed by copyright law, so the earliest they go into public domain is 2067.
Maybe our children or grandchildren will live to see the day that songs by Andrew Sisters or Bing Crosby fall into the public domain.
You may not realize this, but Time-warner owns some recordings by Thomas Alva Edison from the 19th century which won't go into the public domain until 2067.
For sources about music and copyright,
this article and
this one