Year | Value | 2021 | 1.522 | 2020 | 1.529 | 2019 | 1.546 | 2018 | 1.605 | 2017 | 1.649 | 2016 | 1.658 | 2015 | 1.751 | 2014 | 1.871 | 2013 | 2.098 | 2012 | 2.001 | 2011 | 1.992 | 2010 | 2.426 | 2009 | 2.437 | 2008 | 2.444 | 2007 | 2.357 | 2006 | 2.429 | 2005 | 2.609 | 2004 | 2.461 | 2003 | 2.28 | 2002 | 2.533 | 2001 | 2.622 | 2000 | 2.66 | 1999 | 2.641 | 1998 | 2.589 | 1997 | 2.571 | 1996 | 2.599 | 1995 | 2.6 | 1994 | 2.603 | 1993 | 2.728 | 1992 | 2.871 | 1991 | 3.441 | 1990 | 3.647 | 1989 | 3.64 | 1988 | 3.948 | 1987 | 3.753 | 1986 | 4.166 | 1985 | 4.308 | 1984 | 4.594 | 1983 | 4.656 | 1982 | 4.731 | 1981 | 4.458 | 1980 | 4.909 | 1979 | 4.493 | 1978 | 4.69 | 1977 | 4.961 | 1976 | 5.272 | 1975 | 5.249 | 1974 | 5.473 | 1973 | 5.417 | 1972 | 5.616 | 1971 | 5.674 | 1970 | 5.503 | 1969 | 5.857 | 1968 | 5.745 | 1967 | 5.777 | 1966 | 5.737 | 1965 | 5.927 | 1964 | 6.126 | 1963 | 6.296 | 1962 | 6.331 | 1961 | 6.35 | 1960 | 6.359 |
|