Year | Value | 2021 | 52.676 | 2020 | 52.887 | 2019 | 52.91 | 2018 | 52.554 | 2017 | 52.305 | 2016 | 52.043 | 2015 | 51.841 | 2014 | 51.791 | 2013 | 51.707 | 2012 | 51.497 | 2011 | 51.357 | 2010 | 50.945 | 2009 | 50.712 | 2008 | 50.225 | 2007 | 50.033 | 2006 | 49.73 | 2005 | 49.297 | 2004 | 48.767 | 2003 | 48.441 | 2002 | 47.928 | 2001 | 47.619 | 2000 | 47.193 | 1999 | 46.614 | 1998 | 46.036 | 1997 | 45.792 | 1996 | 45.567 | 1995 | 45.487 | 1994 | 45.513 | 1993 | 45.788 | 1992 | 45.668 | 1991 | 45.691 | 1990 | 46.037 | 1989 | 46.182 | 1988 | 46.072 | 1987 | 46.018 | 1986 | 45.975 | 1985 | 46.317 | 1984 | 46.55 | 1983 | 46.638 | 1982 | 46.513 | 1981 | 46.493 | 1980 | 46.349 | 1979 | 46.215 | 1978 | 46.019 | 1977 | 45.558 | 1976 | 44.721 | 1975 | 43.662 | 1974 | 42.791 | 1973 | 42.011 | 1972 | 41.273 | 1971 | 40.48 | 1970 | 39.713 | 1969 | 38.718 | 1968 | 38.482 | 1967 | 37.573 | 1966 | 38.797 | 1965 | 38.68 | 1964 | 38.415 | 1963 | 38.192 | 1962 | 37.809 | 1961 | 37.673 | 1960 | 37.371 |
|