Year | Value | 2021 | 23.529411764706 | 2020 | 23.529411764706 | 2019 | 23.529411764706 | 2018 | 23.529411764706 | 2017 | 23.529411764706 | 2016 | 23.529411764706 | 2015 | 23.529411764706 | 2014 | 23.529411764706 | 2013 | 23.529411764706 | 2012 | 23.529411764706 | 2011 | 29.411764705882 | 2010 | 29.411764705882 | 2009 | 29.411764705882 | 2008 | 26.470588235294 | 2007 | 26.470588235294 | 2006 | 26.470588235294 | 2005 | 26.470588235294 | 2004 | 35.294117647059 | 2003 | 35.294117647059 | 2002 | 38.235294117647 | 2001 | 38.235294117647 | 2000 | 35.294117647059 | 1999 | 35.294117647059 | 1998 | 32.352941176471 | 1997 | 32.352941176471 | 1996 | 32.352941176471 | 1995 | 32.352941176471 | 1994 | 35.294117647059 | 1993 | 35.294117647059 | 1992 | 35.294117647059 | 1991 | 35.294117647059 | 1990 | 38.235294117647 | 1989 | 38.235294117647 | 1988 | 38.235294117647 | 1987 | 38.235294117647 | 1986 | 41.176470588235 | 1985 | 41.176470588235 | 1984 | 47.058823529412 | 1983 | 47.058823529412 | 1982 | 47.058823529412 | 1981 | 47.058823529412 | 1980 | 47.058823529412 | 1979 | 55.882352941176 | 1978 | 55.882352941176 | 1977 | 58.823529411765 | 1976 | 58.823529411765 | 1975 | 58.823529411765 | 1974 | 58.823529411765 | 1973 | 58.823529411765 | 1972 | 58.823529411765 | 1971 | 64.705882352941 | 1970 | 64.705882352941 | 1969 | 64.705882352941 | 1968 | 64.705882352941 | 1967 | 64.705882352941 | 1966 | 64.705882352941 | 1965 | 64.705882352941 | 1964 | 64.705882352941 | 1963 | 64.705882352941 | 1962 | 64.705882352941 | 1961 | 64.705882352941 |
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