Google Books Ngram Viewer

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

1500 - 1668 1669 - 1776 1777 - 1797 1798 - 1995 1996 - 2008 clé French
1500 - 1643 1644 - 1872 1873 - 1903 1904 - 1973 1974 - 2008 clef French

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