Year | Value | 2023 | 10.897 | 2022 | 11.115 | 2021 | 11.377 | 2020 | 11.624 | 2019 | 11.921 | 2018 | 12.004 | 2017 | 12.437 | 2016 | 12.741 | 2015 | 12.582 | 2014 | 13.362 | 2013 | 14.024 | 2012 | 13.99 | 2011 | 13.8 | 2010 | 13.65 | 2009 | 13.649 | 2008 | 13.676 | 2007 | 13.741 | 2006 | 13.81 | 2005 | 13.94 | 2004 | 14.027 | 2003 | 14.291 | 2002 | 14.458 | 2001 | 14.479 | 2000 | 14.377 | 1999 | 15.131 | 1998 | 16.001 | 1997 | 17.532 | 1996 | 19.253 | 1995 | 20.725 | 1994 | 21.672 | 1993 | 22.054 | 1992 | 21.573 | 1991 | 21.344 | 1990 | 22.015 | 1989 | 22.218 | 1988 | 22.02 | 1987 | 22.024 | 1986 | 22.105 | 1985 | 22.348 | 1984 | 22.692 | 1983 | 22.75 | 1982 | 22.687 | 1981 | 22.293 | 1980 | 22.846 | 1979 | 23.82 | 1978 | 25.131 | 1977 | 26.872 | 1976 | 28.794 | 1975 | 29.979 |
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