Hong Kong Supplementary Character Set
Version history

Version
Total characters
Publish date
GCCS
3,049
1995
HKSCS-1999
4,702
09/1999
HKSCS-2001
4,818
12/2001
HKSCS-2004
4,941
05/2005
HKSCS-2008
5,009
12/2009
HKSCS-2016
5,033
05/2017

Question: What supplementary sets were released in 2001 and 2004?
Answer: Hong Kong Supplementary Character Set's revisions were released in 2001 (adding 116 characters) and in 2004 (adding 123 characters), totalling 4,941 characters.