| Year | Value | | 2023 | 380,178 | | 2022 | 365,951 | | 2021 | 352,492 | | 2020 | 339,978 | | 2019 | 332,447 | | 2018 | 323,985 | | 2017 | 315,055 | | 2016 | 314,865 | | 2015 | 326,426 | | 2014 | 347,720 | | 2013 | 374,723 | | 2012 | 401,781 | | 2011 | 421,989 | | 2010 | 437,748 | | 2009 | 449,382 | | 2008 | 451,526 | | 2007 | 450,212 | | 2006 | 450,642 | | 2005 | 447,134 | | 2004 | 439,378 | | 2003 | 429,582 | | 2002 | 417,451 | | 2001 | 403,056 | | 2000 | 387,306 | | 1999 | 371,252 | | 1998 | 358,364 | | 1997 | 349,626 | | 1996 | 342,679 | | 1995 | 336,927 | | 1994 | 331,768 | | 1993 | 328,004 | | 1992 | 326,172 | | 1991 | 324,743 | | 1990 | 331,169 | | 1989 | 344,839 | | 1988 | 356,764 | | 1987 | 360,502 | | 1986 | 360,604 | | 1985 | 363,787 | | 1984 | 371,279 | | 1983 | 381,353 | | 1982 | 390,734 | | 1981 | 399,264 | | 1980 | 406,947 | | 1979 | 415,164 | | 1978 | 412,392 | | 1977 | 395,739 | | 1976 | 372,537 | | 1975 | 350,175 | | 1974 | 330,117 |
|