Year | Value | 2022 | 49.396924370407 | 2021 | 49.386641439112 | 2020 | 49.381073317242 | 2019 | 49.373621246316 | 2018 | 49.366906978114 | 2017 | 49.357837470077 | 2016 | 49.34677958415 | 2015 | 49.333789254394 | 2014 | 49.318311432795 | 2013 | 49.300913585528 | 2012 | 49.282731815203 | 2011 | 49.265027742156 | 2010 | 49.248154225694 | 2009 | 49.230992111587 | 2008 | 49.206147894416 | 2007 | 49.172843638718 | 2006 | 49.137733794868 | 2005 | 49.101614531123 | 2004 | 49.0655764371 | 2003 | 49.030451670787 | 2002 | 48.995235850641 | 2001 | 48.959840111809 | 2000 | 48.925958563991 | 1999 | 48.912981132886 | 1998 | 48.908329826628 | 1997 | 48.893134416366 | 1996 | 48.8804632876 | 1995 | 48.868880061053 | 1994 | 48.859947437754 | 1993 | 48.852940802503 | 1992 | 48.842190847759 | 1991 | 48.827432948667 | 1990 | 48.810703297449 | 1989 | 48.792472213325 | 1988 | 48.779387344737 | 1987 | 48.773246294989 | 1986 | 48.769862982059 | 1985 | 48.764446953371 | 1984 | 48.756487743572 | 1983 | 48.751159504046 | 1982 | 48.747167847342 | 1981 | 48.741619303648 | 1980 | 48.735869606464 | 1979 | 48.802944486014 | 1978 | 48.863973497567 | 1977 | 48.843376370827 | 1976 | 48.820865096533 | 1975 | 48.80563852172 | 1974 | 48.823984070311 | 1973 | 48.861278875067 | 1972 | 48.90678428395 | 1971 | 48.954987698939 | 1970 | 48.992618423654 | 1969 | 49.034335860039 | 1968 | 49.0856199384 | 1967 | 49.12806862607 | 1966 | 49.150173972686 | 1965 | 49.16749357025 | 1964 | 49.177691432338 | 1963 | 49.183601968175 | 1962 | 49.184431559388 | 1961 | 49.182020262815 | 1960 | 49.176066074746 |
|