Google Books Ngram Viewer

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

1800 - 1850 1851 - 1868 1869 1870 - 1976 1977 - 2000 the police force are English
1800 - 1869 1870 - 1900 1901 - 1910 1911 - 1981 1982 - 2000 the police force is English

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