| Year | Value | | 2022 | 28,018,000 | | 2021 | 27,092,000 | | 2020 | 27,013,000 | | 2019 | 27,968,000 | | 2018 | 27,640,000 | | 2017 | 26,660,000 | | 2016 | 26,551,000 | | 2015 | 25,770,000 | | 2014 | 25,060,000 | | 2013 | 24,940,000 | | 2012 | 24,338,000 | | 2011 | 23,789,000 | | 2010 | 22,500,000 | | 2009 | 22,200,000 | | 2008 | 22,120,000 | | 2007 | 21,260,000 | | 2006 | 19,760,000 | | 2005 | 18,420,000 | | 2004 | 16,480,000 | | 2003 | 14,347,000 | | 2002 | 12,670,000 | | 2001 | 11,132,000 | | 2000 | 8,562,000 | | 1999 | 6,315,000 | | 1998 | 4,918,000 | | 1997 | 4,578,000 | | 1996 | 3,990,000 | | 1995 | 2,242,000 | | 1994 | 1,220,000 | | 1993 | 690,000 | | 1992 | 497,000 | | 1991 | 291,459 | | 1990 | 184,943 | | 1989 | 94,529 | | 1988 | 31,622 | | 1987 | 4,423 |
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