| Year | Value | | 2023 | 339,659 | | 2022 | 328,127 | | 2021 | 317,201 | | 2020 | 308,588 | | 2019 | 305,195 | | 2018 | 306,896 | | 2017 | 313,126 | | 2016 | 324,447 | | 2015 | 340,175 | | 2014 | 358,792 | | 2013 | 379,361 | | 2012 | 400,488 | | 2011 | 420,293 | | 2010 | 437,849 | | 2009 | 453,058 | | 2008 | 460,152 | | 2007 | 461,872 | | 2006 | 462,256 | | 2005 | 456,538 | | 2004 | 445,735 | | 2003 | 434,316 | | 2002 | 423,376 | | 2001 | 411,011 | | 2000 | 398,620 | | 1999 | 387,270 | | 1998 | 376,054 | | 1997 | 364,655 | | 1996 | 354,503 | | 1995 | 345,397 | | 1994 | 337,005 | | 1993 | 331,667 | | 1992 | 329,687 | | 1991 | 327,433 | | 1990 | 328,185 | | 1989 | 332,814 | | 1988 | 340,523 | | 1987 | 348,255 | | 1986 | 356,456 | | 1985 | 366,497 | | 1984 | 375,427 | | 1983 | 383,004 | | 1982 | 390,454 | | 1981 | 396,503 | | 1980 | 398,721 | | 1979 | 398,887 | | 1978 | 394,001 | | 1977 | 382,945 | | 1976 | 366,437 | | 1975 | 347,927 | | 1974 | 329,375 |
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