Year | Value | 2022 | 49.354284963596 | 2021 | 49.371621586401 | 2020 | 49.385125231572 | 2019 | 49.449738163619 | 2018 | 49.44634660628 | 2017 | 49.398559675909 | 2016 | 49.427068938369 | 2015 | 49.453049455181 | 2014 | 49.474728187155 | 2013 | 49.492284347672 | 2012 | 49.500253632531 | 2011 | 49.503765922142 | 2010 | 49.510581021034 | 2009 | 49.520392749245 | 2008 | 49.531667303107 | 2007 | 49.542747292731 | 2006 | 49.555498442984 | 2005 | 49.570465098433 | 2004 | 49.586206202854 | 2003 | 49.595302607051 | 2002 | 49.592451379994 | 2001 | 49.581645930926 | 2000 | 49.566957012923 | 1999 | 49.547640473061 | 1998 | 49.525421575044 | 1997 | 49.500658454426 | 1996 | 49.474983395973 | 1995 | 49.446658660781 | 1994 | 49.418532600502 | 1993 | 49.392784497585 | 1992 | 49.364576479675 | 1991 | 49.343293422705 | 1990 | 49.329298449149 | 1989 | 49.32089868701 | 1988 | 49.31715774824 | 1987 | 49.313125364197 | 1986 | 49.30894495837 | 1985 | 49.301227670166 | 1984 | 49.290756361778 | 1983 | 49.278540697449 | 1982 | 49.266393635019 | 1981 | 49.252843743621 | 1980 | 49.231817615282 | 1979 | 49.206475914703 | 1978 | 49.181642429194 | 1977 | 49.158186980998 | 1976 | 49.138686965232 | 1975 | 49.121235977544 | 1974 | 49.101948494743 | 1973 | 49.082536475342 | 1972 | 49.063958482153 | 1971 | 49.038232631538 | 1970 | 48.991220827107 | 1969 | 48.945692225916 | 1968 | 48.915985556999 | 1967 | 48.885939077636 | 1966 | 48.855285287439 | 1965 | 48.820569834724 | 1964 | 48.778987353869 | 1963 | 48.728514897118 | 1962 | 48.671497473903 | 1961 | 48.615724843563 | 1960 | 48.554016128231 |
|