| Year | Value | | 2021 | 20,181 | | 2020 | 221,654 | | 2019 | 236,601 | | 2018 | 272,347 | | 2017 | 284,935 | | 2016 | 280,090 | | 2015 | 259,682 | | 2014 | 269,148 | | 2013 | 255,204 | | 2012 | 240,525.44145286 | | 2011 | 204,096.67597181 | | 2010 | 214,667 | | 2009 | 303,117 | | 2008 | 329,788 | | 2007 | 324,821 | | 2006 | 306,504 | | 2005 | 315,410 | | 2004 | 289,309 | | 2003 | 258,311 | | 2002 | 191,094 | | 2001 | 202,899 | | 2000 | 232,649 | | 1999 | 307,500 | | 1998 | 277,700 | | 1997 | 278,800 | | 1996 | 194,700 | | 1995 | 161,800 | | 1994 | 148,900 | | 1993 | 96,000 | | 1992 | 123,000 | | 1991 | 150,000 | | 1990 | 132,500 | | 1989 | 132,500 | | 1988 | 135,000 | | 1987 | 110,400 | | 1986 | 89,200 | | 1985 | 108,000 | | 1984 | 117,000 | | 1983 | 106,000 | | 1982 | 107,000 | | 1981 | 144,000 | | 1980 | 144,000 | | 1979 | 146,400 | | 1978 | 120,000 | | 1977 | 53,000 | | 1976 | 50,000 |
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