Year | Value | 2021 | 20,653.338 | 2020 | 30,407.914 | 2019 | 64,320 | 2018 | 64,397.964489686 | 2017 | 62,480 | 2016 | 65,643 | 2015 | 51,652 | 2014 | 49,599 | 2013 | 38,028 | 2012 | 37,798.829816477 | 2011 | 32,354 | 2010 | 20,485 | 2009 | 28,499 | 2008 | 29,514 | 2007 | 29,235 | 2006 | 28,700 | 2005 | 26,460 | 2004 | 24,729 | 2003 | 20,611 | 2002 | 20,624 | 2001 | 9,709 | 2000 | 10,329 | 1999 | 11,300 | 1998 | 14,700 | 1997 | 14,500 | 1996 | 14,500 | 1995 | 14,500 | 1994 | 13,800 | 1993 | 13,800 | 1992 | 13,800 | 1991 | 13,800 | 1990 | 13,800 | 1989 | 13,800 | 1988 | 22,600 | 1987 | 22,500 | 1986 | 22,500 | 1985 | 22,500 | 1984 | 21,700 | 1983 | 22,300 | 1982 | 21,500 | 1981 | 19,500 | 1980 | 19,400 | 1979 | 18,500 | 1978 | 17,400 | 1977 | 17,400 | 1976 | 17,200 | 1975 | 17,100 | 1974 | 17,900 | 1973 | 23,500 | 1972 | 22,900 | 1971 | 22,500 | 1970 | 21,700 |
|