Google Books Ngram Viewer

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

1900 - 1954 1955 - 1958 1959 1960 - 1980 1981 - 1980 conspiracy theory English
1900 - 1964 1965 - 1974 1975 1976 - 1978 1979 - 1980 conspiracy theorist English

Run your own experiment! Raw data is available for download here.
© 2013 Google - Privacy & Terms - About Google - About Google Books - About Ngram Viewer