Year | Value | 2021 | 1.581 | 2020 | 1.591 | 2019 | 1.601 | 2018 | 1.61 | 2017 | 1.627 | 2016 | 1.673 | 2015 | 1.73 | 2014 | 1.794 | 2013 | 1.862 | 2012 | 1.93 | 2011 | 1.99 | 2010 | 1.846 | 2009 | 1.713 | 2008 | 1.735 | 2007 | 1.565 | 2006 | 1.764 | 2005 | 1.705 | 2004 | 1.702 | 2003 | 1.723 | 2002 | 1.753 | 2001 | 1.8 | 2000 | 1.85 | 1999 | 1.909 | 1998 | 1.992 | 1997 | 2.07 | 1996 | 2.129 | 1995 | 2.16 | 1994 | 2.157 | 1993 | 2.14 | 1992 | 2.097 | 1991 | 2.046 | 1990 | 2.033 | 1989 | 2.055 | 1988 | 2.082 | 1987 | 2.104 | 1986 | 2.117 | 1985 | 2.138 | 1984 | 2.204 | 1983 | 2.277 | 1982 | 2.35 | 1981 | 2.423 | 1980 | 2.484 | 1979 | 2.55 | 1978 | 2.614 | 1977 | 2.677 | 1976 | 2.757 | 1975 | 2.827 | 1974 | 2.912 | 1973 | 2.988 | 1972 | 3.066 | 1971 | 3.151 | 1970 | 3.247 | 1969 | 3.335 | 1968 | 3.426 | 1967 | 3.522 | 1966 | 3.621 | 1965 | 3.729 | 1964 | 3.829 | 1963 | 3.918 | 1962 | 4.027 | 1961 | 4.11 | 1960 | 4.202 |
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