| Year | Value | | 2022 | 17,948,623 | | 2021 | 17,008,910 | | 2020 | 16,543,805 | | 2019 | 18,476,236 | | 2018 | 20,731,169 | | 2017 | 24,493,687 | | 2016 | 27,600,893 | | 2015 | 29,093,517 | | 2014 | 30,528,022 | | 2013 | 30,896,079 | | 2012 | 30,569,073 | | 2011 | 28,781,999 | | 2010 | 27,880,132 | | 2009 | 28,123,570 | | 2008 | 27,414,377 | | 2007 | 23,820,133 | | 2006 | 18,789,466 | | 2005 | 12,495,721 | | 2004 | 8,420,980 | | 2003 | 7,015,121 | | 2002 | 6,541,894 | | 2001 | 6,472,584 | | 2000 | 5,447,172 | | 1999 | 3,784,735 | | 1998 | 2,009,757 | | 1997 | 1,071,900 | | 1996 | 581,700 | | 1995 | 403,800 | | 1994 | 319,000 | | 1993 | 182,600 | | 1992 | 78,560 | | 1991 | 16,600 | | 1990 | 7,422 | | 1989 | 3,685 | | 1988 | 1,800 |
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