Year | Value | 2022 | 12.426 | 2021 | 14.657 | 2020 | 15.899 | 2019 | 17.045 | 2018 | 19.179 | 2017 | 21.414 | 2016 | 23.514 | 2015 | 24.981 | 2014 | 26.708 | 2013 | 27.686 | 2012 | 24.731 | 2011 | 17.973 | 2010 | 12.719 | 2009 | 9.546 | 2008 | 7.664 | 2007 | 8.351 | 2006 | 8.906 | 2005 | 10.074 | 2004 | 10.628 | 2003 | 9.839 | 2002 | 10.346 | 2001 | 11.02 | 2000 | 11.345 | 1999 | 12.138 | 1998 | 12.227 | 1997 | 10.472 | 1996 | 10.402 | 1995 | 10.117 | 1994 | 9.808 | 1993 | 10.177 | 1992 | 8.927 | 1991 | 8.03 | 1990 | 7.012 | 1989 | 7.505 | 1988 | 7.828 | 1987 | 7.448 | 1986 | 7.356 | 1985 | 7.8 | 1984 | 8.1 | 1983 | 7.804 | 1982 | 4.94 | 1981 | 3.42 |
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