Google Books Ngram Viewer

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

1500 - 1950 1951 - 1958 1959 - 1960 1961 - 1997 1998 - 2008 port harcourt English

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