Year | Value | 2021 | 70.29 | 2020 | 70.86 | 2019 | 71.07 | 2018 | 71.27 | 2017 | 71.3 | 2016 | 71.19 | 2015 | 71.08 | 2014 | 70.97 | 2013 | 70.7 | 2012 | 70.4 | 2011 | 69.74 | 2010 | 69.46 | 2009 | 69.38 | 2008 | 69.2 | 2007 | 69.2 | 2006 | 69.12 | 2005 | 69.12 | 2004 | 68.9 | 2003 | 68.8 | 2002 | 68.6 | 2001 | 68.4 | 2000 | 68.2 | 1999 | 67.4 | 1998 | 66.9 | 1997 | 66.6 | 1996 | 66.44 | 1995 | 66.56 | 1994 | 66.5 | 1993 | 66.4 | 1992 | 66.4 | 1991 | 66.2 | 1990 | 65.6 | 1989 | 65.25 | 1988 | 64.73 | 1987 | 64.696 | 1986 | 64.393 | 1985 | 64.136 | 1984 | 64.02 | 1983 | 64.031 | 1982 | 63.825 | 1981 | 63.186 | 1980 | 62.156 | 1979 | 61.424 | 1978 | 60.711 | 1977 | 59.946 | 1976 | 58.898 | 1975 | 58.728 | 1974 | 58.094 | 1973 | 58.085 | 1972 | 57.632 | 1971 | 58.008 | 1970 | 58.035 | 1969 | 57.115 | 1968 | 55.959 | 1967 | 55.442 | 1966 | 56.238 | 1965 | 56.742 | 1964 | 56.56 | 1963 | 55.882 | 1962 | 55.023 | 1961 | 53.961 | 1960 | 52.828 |
|