| Year | Value | | 2023 | 12,612,034 | | 2022 | 12,556,766 | | 2021 | 12,496,843 | | 2020 | 12,423,573 | | 2019 | 12,349,492 | | 2018 | 12,277,255 | | 2017 | 12,192,797 | | 2016 | 12,096,240 | | 2015 | 11,996,683 | | 2014 | 11,895,011 | | 2013 | 11,787,501 | | 2012 | 11,675,975 | | 2011 | 11,562,483 | | 2010 | 11,448,597 | | 2009 | 11,334,501 | | 2008 | 11,214,930 | | 2007 | 11,052,339 | | 2006 | 10,877,511 | | 2005 | 10,706,683 | | 2004 | 10,536,102 | | 2003 | 10,366,101 | | 2002 | 10,197,652 | | 2001 | 10,030,580 | | 2000 | 9,866,433 | | 1999 | 9,701,260 | | 1998 | 9,527,218 | | 1997 | 9,367,028 | | 1996 | 9,205,191 | | 1995 | 9,029,249 | | 1994 | 8,833,917 | | 1993 | 8,544,452 | | 1992 | 8,140,560 | | 1991 | 7,788,327 | | 1990 | 7,525,534 | | 1989 | 7,267,204 | | 1988 | 7,038,989 | | 1987 | 6,814,430 | | 1986 | 6,570,192 | | 1985 | 6,348,527 | | 1984 | 6,161,834 | | 1983 | 5,964,941 | | 1982 | 5,757,086 | | 1981 | 5,553,511 | | 1980 | 5,585,386 | | 1979 | 5,688,760 | | 1978 | 5,628,678 | | 1977 | 5,726,952 | | 1976 | 6,003,119 | | 1975 | 6,426,713 | | 1974 | 4,904,717 |
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