Google Books Ngram Viewer

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

1800 - 1889 1890 - 1912 1913 - 1921 1922 - 1993 1994 - 2008 efficiency English
1800 - 1815 1816 - 1830 1831 - 1887 1888 - 1991 1992 - 2008 equity English

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