| Year | Value | | 2023 | 38,438,241 | | 2022 | 37,940,098 | | 2021 | 37,415,128 | | 2020 | 36,845,215 | | 2019 | 36,256,070 | | 2018 | 35,651,638 | | 2017 | 35,010,812 | | 2016 | 34,330,176 | | 2015 | 33,643,727 | | 2014 | 32,961,669 | | 2013 | 32,263,554 | | 2012 | 31,555,235 | | 2011 | 30,844,842 | | 2010 | 30,076,202 | | 2009 | 28,980,751 | | 2008 | 27,887,770 | | 2007 | 26,807,406 | | 2006 | 25,743,722 | | 2005 | 24,697,777 | | 2004 | 23,673,351 | | 2003 | 22,665,586 | | 2002 | 21,679,640 | | 2001 | 20,717,173 | | 2000 | 19,775,633 | | 1999 | 19,293,391 | | 1998 | 18,945,894 | | 1997 | 18,595,082 | | 1996 | 18,245,060 | | 1995 | 17,892,581 | | 1994 | 17,539,430 | | 1993 | 17,184,570 | | 1992 | 16,824,677 | | 1991 | 16,464,786 | | 1990 | 16,106,206 | | 1989 | 15,706,125 | | 1988 | 15,306,624 | | 1987 | 14,907,775 | | 1986 | 14,514,546 | | 1985 | 14,123,568 | | 1984 | 13,735,567 | | 1983 | 13,349,822 | | 1982 | 12,969,819 | | 1981 | 12,598,303 | | 1980 | 12,230,097 | | 1979 | 11,735,011 | | 1978 | 11,212,605 | | 1977 | 10,702,425 | | 1976 | 10,208,083 | | 1975 | 9,726,526 | | 1974 | 9,254,688 |
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