Google Books Ngram Viewer

Graph these comma-separated phrases:
case-insensitive
between and from the corpus with smoothing of .  
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1965 - 1980 1981 - 1996 1997 1998 1999 online comments English
1965 - 1966 1967 - 1992 1993 1994 - 1996 1997 - 1998 correlation does not equal causation English

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