| Year | Value | | 2024 | 26,951 | | 2023 | 26,392 | | 2022 | 25,946 | | 2021 | 25,963 | | 2020 | 26,400 | | 2019 | 26,680 | | 2018 | 26,852 | | 2017 | 27,109 | | 2016 | 27,363 | | 2015 | 27,586 | | 2014 | 27,776 | | 2013 | 27,867 | | 2012 | 27,732 | | 2011 | 27,302 | | 2010 | 26,554 | | 2009 | 25,477 | | 2008 | 24,127 | | 2007 | 22,618 | | 2006 | 21,616 | | 2005 | 21,173 | | 2004 | 20,752 | | 2003 | 20,395 | | 2002 | 20,147 | | 2001 | 20,084 | | 2000 | 20,119 | | 1999 | 20,127 | | 1998 | 20,099 | | 1997 | 20,079 | | 1996 | 20,038 | | 1995 | 19,971 | | 1994 | 19,033 | | 1993 | 17,283 | | 1992 | 15,950 | | 1991 | 15,087 | | 1990 | 14,395 | | 1989 | 13,780 | | 1988 | 13,230 | | 1987 | 12,718 | | 1986 | 12,265 | | 1985 | 11,889 | | 1984 | 11,604 | | 1983 | 11,362 | | 1982 | 11,106 | | 1981 | 10,836 | | 1980 | 10,573 | | 1979 | 10,371 | | 1978 | 10,230 | | 1977 | 10,060 | | 1976 | 9,843 | | 1975 | 9,593 |
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