| Year | Value | | 2023 | 18,881,435 | | 2022 | 18,242,785 | | 2021 | 17,541,680 | | 2020 | 16,722,952 | | 2019 | 16,170,475 | | 2018 | 15,499,088 | | 2017 | 14,847,009 | | 2016 | 14,163,205 | | 2015 | 13,550,001 | | 2014 | 13,026,478 | | 2013 | 12,561,282 | | 2012 | 12,143,029 | | 2011 | 11,740,672 | | 2010 | 11,353,046 | | 2009 | 10,979,617 | | 2008 | 10,622,845 | | 2007 | 10,281,641 | | 2006 | 9,960,400 | | 2005 | 9,660,213 | | 2004 | 9,377,842 | | 2003 | 9,100,783 | | 2002 | 8,810,532 | | 2001 | 8,537,792 | | 2000 | 8,289,243 | | 1999 | 8,041,854 | | 1998 | 7,793,558 | | 1997 | 7,594,788 | | 1996 | 7,415,858 | | 1995 | 7,273,738 | | 1994 | 7,137,229 | | 1993 | 6,926,204 | | 1992 | 6,706,125 | | 1991 | 6,492,431 |
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