| Year | Value | | 2023 | 22,884,069 | | 2022 | 22,526,660 | | 2021 | 22,303,449 | | 2020 | 24,060,818 | | 2019 | 23,943,305 | | 2018 | 24,412,306 | | 2017 | 24,004,375 | | 2016 | 24,239,329 | | 2015 | 24,454,335 | | 2014 | 24,256,532 | | 2013 | 24,061,830 | | 2012 | 23,865,743 | | 2011 | 23,653,727 | | 2010 | 23,425,673 | | 2009 | 23,281,426 | | 2008 | 23,190,340 | | 2007 | 23,098,783 | | 2006 | 23,010,264 | | 2005 | 22,936,884 | | 2004 | 22,864,534 | | 2003 | 22,785,706 | | 2002 | 22,698,391 | | 2001 | 22,552,663 | | 2000 | 22,362,877 | | 1999 | 22,179,656 | | 1998 | 21,922,074 | | 1997 | 21,569,833 | | 1996 | 21,224,098 | | 1995 | 20,904,851 | | 1994 | 20,599,910 | | 1993 | 20,308,534 | | 1992 | 20,000,244 | | 1991 | 19,749,032 |
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