Year | Value | 2022 | 17.95 | 2021 | 18.26 | 2020 | 18.575 | 2019 | 18.896 | 2018 | 19.222 | 2017 | 19.554 | 2016 | 19.892 | 2015 | 20.236 | 2014 | 20.585 | 2013 | 20.939 | 2012 | 21.299 | 2011 | 21.665 | 2010 | 22.036 | 2009 | 22.413 | 2008 | 22.796 | 2007 | 23.184 | 2006 | 23.577 | 2005 | 23.976 | 2004 | 24.38 | 2003 | 24.789 | 2002 | 25.203 | 2001 | 25.621 | 2000 | 26.043 | 1999 | 26.47 | 1998 | 26.902 | 1997 | 27.338 | 1996 | 27.777 | 1995 | 28.223 | 1994 | 28.672 | 1993 | 29.126 | 1992 | 29.585 | 1991 | 30.051 | 1990 | 30.519 | 1989 | 30.992 | 1988 | 31.468 | 1987 | 31.949 | 1986 | 32.434 | 1985 | 32.966 | 1984 | 33.613 | 1983 | 34.267 | 1982 | 34.927 | 1981 | 35.592 | 1980 | 36.262 | 1979 | 36.939 | 1978 | 37.621 | 1977 | 38.307 | 1976 | 38.997 | 1975 | 39.694 | 1974 | 40.393 | 1973 | 41.11 | 1972 | 41.857 | 1971 | 42.61 | 1970 | 43.365 | 1969 | 44.123 | 1968 | 44.883 | 1967 | 45.648 | 1966 | 46.413 | 1965 | 47.18 | 1964 | 47.973 | 1963 | 49.416 | 1962 | 50.857 | 1961 | 52.298 | 1960 | 53.732 |
|