Year | Value | 2022 | 24.534552210688 | 2021 | 24.803570020256 | 2020 | 25.039459931855 | 2019 | 25.261336622254 | 2018 | 25.483064604921 | 2017 | 25.692973324023 | 2016 | 25.895375703333 | 2015 | 26.092227688048 | 2014 | 26.282523719486 | 2013 | 26.460882851645 | 2012 | 26.643378465224 | 2011 | 26.832176736271 | 2010 | 27.027845897936 | 2009 | 27.236690341768 | 2008 | 27.445028192352 | 2007 | 27.663635823978 | 2006 | 27.883359280664 | 2005 | 28.100038996133 | 2004 | 28.318819920567 | 2003 | 28.537153269088 | 2002 | 28.759516897869 | 2001 | 28.987683460032 | 2000 | 29.174209142022 | 1999 | 29.330210536099 | 1998 | 29.466824687177 | 1997 | 29.598452575014 | 1996 | 29.733162813255 | 1995 | 29.873135423633 | 1994 | 30.013929173233 | 1993 | 30.1542820461 | 1992 | 30.28407244664 | 1991 | 30.44096307896 | 1990 | 30.633321020317 | 1989 | 30.802901003379 | 1988 | 30.956950497751 | 1987 | 31.161795418962 | 1986 | 31.370888592697 | 1985 | 31.5213424932 | 1984 | 31.644557256594 | 1983 | 31.777956975248 | 1982 | 31.941168328319 | 1981 | 32.138500475653 | 1980 | 32.411013982937 | 1979 | 32.719886885178 | 1978 | 33.044411952747 | 1977 | 33.380878621811 | 1976 | 33.707885354156 | 1975 | 34.015347191523 | 1974 | 34.352244901527 | 1973 | 34.732253969032 | 1972 | 35.124505836779 | 1971 | 35.535734223938 | 1970 | 35.981917225665 | 1969 | 36.428819046227 | 1968 | 36.882565398918 | 1967 | 37.387862938855 | 1966 | 37.926870982291 | 1965 | 38.497871210476 | 1964 | 39.084159404997 | 1963 | 39.666752706654 | 1962 | 40.250000980568 | 1961 | 40.784515683806 | 1960 | 41.322931636408 |
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