Year | Value | 2023 | 53.608 | 2022 | 52.889 | 2021 | 52.163 | 2020 | 51.43 | 2019 | 50.692 | 2018 | 49.949 | 2017 | 49.2 | 2016 | 48.448 | 2015 | 47.694 | 2014 | 46.943 | 2013 | 46.193 | 2012 | 45.445 | 2011 | 44.698 | 2010 | 43.856 | 2009 | 42.543 | 2008 | 41.242 | 2007 | 39.95 | 2006 | 38.673 | 2005 | 37.411 | 2004 | 36.169 | 2003 | 34.941 | 2002 | 33.734 | 2001 | 32.548 | 2000 | 31.386 | 1999 | 30.969 | 1998 | 30.795 | 1997 | 30.622 | 1996 | 30.449 | 1995 | 30.276 | 1994 | 30.105 | 1993 | 29.934 | 1992 | 29.763 | 1991 | 29.593 | 1990 | 29.424 | 1989 | 29.167 | 1988 | 28.897 | 1987 | 28.628 | 1986 | 28.361 | 1985 | 28.095 | 1984 | 27.832 | 1983 | 27.569 | 1982 | 27.308 | 1981 | 27.049 | 1980 | 26.791 | 1979 | 26.242 | 1978 | 25.606 | 1977 | 24.98 | 1976 | 24.365 | 1975 | 23.758 | 1974 | 23.164 |
|