Year | Value | 2022 | 17.052402135429 | 2021 | 17.249985575152 | 2020 | 17.446330548796 | 2019 | 17.638310973406 | 2018 | 17.826935591188 | 2017 | 18.010360194511 | 2016 | 18.191229993099 | 2015 | 18.366906307181 | 2014 | 18.540128049178 | 2013 | 18.709625813132 | 2012 | 18.875698776391 | 2011 | 19.03735796291 | 2010 | 19.208014362853 | 2009 | 19.375247656157 | 2008 | 19.544420405476 | 2007 | 19.714670094877 | 2006 | 19.885903473059 | 2005 | 20.04899077698 | 2004 | 20.210706636575 | 2003 | 20.375223820117 | 2002 | 20.53985757183 | 2001 | 20.705358157125 | 2000 | 20.897575877952 | 1999 | 21.21833098938 | 1998 | 21.584506808721 | 1997 | 21.954794605157 | 1996 | 22.328315560403 | 1995 | 22.696973864658 | 1994 | 23.066807159322 | 1993 | 23.441219199237 | 1992 | 23.819426011325 | 1991 | 24.202227593925 | 1990 | 24.566730614447 | 1989 | 24.759098542858 | 1988 | 24.894635333207 | 1987 | 25.031458621027 | 1986 | 25.168425661058 | 1985 | 25.318307594409 | 1984 | 25.469199249396 | 1983 | 25.620273553476 | 1982 | 25.773238087168 | 1981 | 25.926548464263 | 1980 | 26.068873299981 | 1979 | 26.114873027844 | 1978 | 26.12755251287 | 1977 | 26.139418991108 | 1976 | 26.15256204968 | 1975 | 26.151695132976 | 1974 | 26.149871484099 | 1973 | 26.148171659592 | 1972 | 26.146139453054 | 1971 | 26.143873653835 | 1970 | 26.198342099801 | 1969 | 26.488776098392 | 1968 | 26.861450309928 | 1967 | 27.237801565865 | 1966 | 27.617384295137 | 1965 | 28.021282360367 | 1964 | 28.430612346039 | 1963 | 28.843634586084 | 1962 | 29.260216288025 | 1961 | 29.680454760343 | 1960 | 30.081598938674 |
|