Google Books Ngram Viewer

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

1935 - 1944 1945 - 1965 1966 - 1969 1970 - 1984 1985 - 1989 approximation English

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