Google Books Ngram Viewer

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

1960 - 1967 1968 - 1974 1975 - 1977 1978 - 2003 2004 - 2008 reached the mandatory retirement age English
1960 - 1978 1979 1980 1981 - 2000 2001 - 2008 of the mandatory retirement age English
1960 - 1967 1968 - 1987 1988 - 1990 1991 - 2001 2002 - 2008 reaching the mandatory retirement age English
1960 - 1978 1979 - 1987 1988 1989 - 2000 2001 - 2008 raising the mandatory retirement age English
1960 - 1970 1971 - 1986 1987 - 1989 1990 - 2006 2007 - 2008 until the mandatory retirement age English
1960 - 1975 1976 - 1989 1990 - 1991 1992 - 2002 2003 - 2008 at the mandatory retirement age English
1960 - 1978 1979 - 1987 1988 1989 - 2000 2001 - 2008 in the mandatory retirement age English
1960 - 1974 1975 - 1976 1977 - 1988 1989 - 2004 2005 - 2008 reach the mandatory retirement age English
1960 - 1967 1968 - 1979 1980 - 1981 1982 - 1998 1999 - 2008 before the mandatory retirement age English
1960 - 1979 1980 - 1982 1983 1984 - 2004 2005 - 2008 raised the mandatory retirement age English

Excluding ngrams with part-of-speech tags from search links.

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