Year | Value | 2017 | 74.7 | 2016 | 74.5 | 2015 | 75.1 | 2014 | 75 | 2013 | 74.9 | 2012 | 74.5 | 2011 | 74.4 | 2009 | 72.4 | 2008 | 71.7 | 2007 | 71.9 | 2006 | 71.1 | 2005 | 70.674 | 2004 | 70.546 | 2003 | 70.534 | 2002 | 70.413 | 2001 | 70.341 | 2000 | 70.332 | 1999 | 70.26 | 1998 | 70.191 | 1997 | 70.148 | 1996 | 70.126 | 1995 | 70.075 | 1994 | 70.073 | 1993 | 70.041 | 1992 | 69.981 | 1991 | 69.918 | 1990 | 69.846 | 1989 | 69.615 | 1988 | 69.675 | 1987 | 69.613 | 1986 | 69.543 | 1985 | 69.477 | 1984 | 68.977 | 1983 | 68.96 | 1982 | 68.863 | 1981 | 68.73 | 1980 | 68.602 | 1979 | 68.448 | 1978 | 68.019 | 1977 | 67.893 | 1976 | 67.751 | 1975 | 67.17 | 1974 | 67.05 | 1973 | 66.94 | 1972 | 66.325 | 1971 | 66.215 | 1970 | 66.044 | 1969 | 65.597 | 1968 | 65.476 | 1967 | 65.311 | 1966 | 64.863 | 1965 | 64.675 | 1964 | 64.351 | 1963 | 64.167 | 1962 | 64.04 | 1961 | 63.641 | 1960 | 63.559 |
|