| Year | Value | | 2022 | 20,737,000 | | 2021 | 21,888,000 | | 2020 | 21,415,000 | | 2019 | 21,762,000 | | 2018 | 21,108,000 | | 2017 | 20,532,000 | | 2016 | 20,890,000 | | 2015 | 20,809,054 | | 2014 | 19,562,000 | | 2013 | 19,467,000 | | 2012 | 19,717,000 | | 2011 | 19,829,309 | | 2010 | 19,179,000 | | 2009 | 20,149,000 | | 2008 | 20,627,000 | | 2007 | 19,285,000 | | 2006 | 17,296,000 | | 2005 | 15,834,000 | | 2004 | 14,800,000 | | 2003 | 13,200,000 | | 2002 | 12,100,000 | | 2001 | 12,200,000 | | 2000 | 10,755,000 | | 1999 | 6,745,460 | | 1998 | 3,351,000 | | 1997 | 1,717,000 | | 1996 | 1,016,000 | | 1995 | 539,000 | | 1994 | 321,000 | | 1993 | 216,000 | | 1992 | 166,000 | | 1991 | 115,000 | | 1990 | 79,000 | | 1989 | 56,000 | | 1988 | 33,000 | | 1987 | 24,200 | | 1986 | 15,300 | | 1985 | 4,800 |
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