new hosts appearing between 2011-05-16 and 2011-05-23:
sify.com
www.debian.org
www.ethz.ch
www.mhlw.go.jp
www.plurk.com

hosts disappearing between 2011-05-16 and 2011-05-23:
www.cfos.de
www.edu.cn
www.iij4u.or.jp
www.leganerd.com
www.netregistry.com.au
www.neu6.edu.cn
www.nihon-u.ac.jp
www.sannet.ne.jp
www.tokyohive.com
www.tokyotosho.info
www.tradebit.com