Google Books Ngram Viewer

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

1960 - 1969 1970 - 1971 1972 1973 - 2001 2002 - 2008 bilingual skill English
1960 - 1975 1976 - 1997 1998 - 2000 2001 - 2004 2005 - 2008 bilingual skills English

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