Google Books Ngram Viewer

Graph these comma-separated phrases:
case-insensitive
between and from the corpus with smoothing of .  
Search in Google Books:

1993 1994 - 2003 2004 2005 - 2006 2007 - 2008 federal subject English
1993 - 1996 1997 - 1999 2000 2001 - 2003 2004 - 2005 constituent entity English

Run your own experiment! Raw data is available for download here.
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