Year | Value | 2021 | 16.817 | 2020 | 17.037 | 2019 | 17.338 | 2018 | 17.658 | 2017 | 17.996 | 2016 | 18.224 | 2015 | 18.74 | 2014 | 19.339 | 2013 | 20.1 | 2012 | 21.004 | 2011 | 21.702 | 2010 | 21.892 | 2009 | 22.142 | 2008 | 22.379 | 2007 | 22.637 | 2006 | 22.898 | 2005 | 23.2 | 2004 | 23.597 | 2003 | 24.019 | 2002 | 24.46 | 2001 | 24.912 | 2000 | 25.402 | 1999 | 25.926 | 1998 | 26.411 | 1997 | 26.796 | 1996 | 27.259 | 1995 | 27.678 | 1994 | 28.129 | 1993 | 28.522 | 1992 | 28.972 | 1991 | 29.499 | 1990 | 29.969 | 1989 | 30.495 | 1988 | 31.004 | 1987 | 31.534 | 1986 | 32.083 | 1985 | 32.539 | 1984 | 33.022 | 1983 | 33.515 | 1982 | 33.991 | 1981 | 34.517 | 1980 | 35.008 | 1979 | 35.53 | 1978 | 36.034 | 1977 | 36.616 | 1976 | 37.229 | 1975 | 37.878 | 1974 | 38.503 | 1973 | 39.172 | 1972 | 39.815 | 1971 | 40.354 | 1970 | 40.979 | 1969 | 41.611 | 1968 | 41.976 | 1967 | 42.358 | 1966 | 42.653 | 1965 | 43.144 | 1964 | 43.426 | 1963 | 43.619 | 1962 | 43.89 | 1961 | 44.027 | 1960 | 43.969 |
|