Year | Value | 2021 | 12.482 | 2020 | 12.65 | 2019 | 12.871 | 2018 | 13.789 | 2017 | 14.912 | 2016 | 16.076 | 2015 | 17.152 | 2014 | 17.743 | 2013 | 18.218 | 2012 | 18.541 | 2011 | 18.994 | 2010 | 19.541 | 2009 | 20.009 | 2008 | 20.651 | 2007 | 21.078 | 2006 | 21.337 | 2005 | 22 | 2004 | 22.451 | 2003 | 22.386 | 2002 | 23.399 | 2001 | 24.384 | 2000 | 25.58 | 1999 | 26.845 | 1998 | 28.097 | 1997 | 29.235 | 1996 | 30.673 | 1995 | 31.978 | 1994 | 33.207 | 1993 | 34.249 | 1992 | 35.21 | 1991 | 36.161 | 1990 | 36.986 | 1989 | 37.809 | 1988 | 38.504 | 1987 | 39.199 | 1986 | 39.864 | 1985 | 40.374 | 1984 | 41.001 | 1983 | 41.59 | 1982 | 42.166 | 1981 | 42.727 | 1980 | 43.268 | 1979 | 43.777 | 1978 | 44.242 | 1977 | 44.664 | 1976 | 45.047 | 1975 | 45.399 | 1974 | 45.729 | 1973 | 46.187 | 1972 | 46.592 | 1971 | 46.977 | 1970 | 47.373 | 1969 | 47.753 | 1968 | 48.077 | 1967 | 48.347 | 1966 | 48.561 | 1965 | 48.703 | 1964 | 48.757 | 1963 | 48.772 | 1962 | 48.725 | 1961 | 48.682 | 1960 | 48.624 |
|