| Year | Value | | 2018 | 6,645,652.5139884 | | 2017 | 5,816,851 | | 2016 | 5,986,259 | | 2015 | 5,845,803 | | 2014 | 6,162,872.3288798 | | 2013 | 5,475,499.6 | | 2012 | 5,920,044.8964502 | | 2011 | 5,829,441.1760114 | | 2010 | 4,996,231 | | 2009 | 4,424,144 | | 2008 | 4,978,399 | | 2007 | 4,918,479 | | 2006 | 4,645,698 | | 2005 | 4,742,561 | | 2004 | 5,043,466 | | 2003 | 6,210,378 | | 2002 | 6,306,172 | | 2001 | 6,579,219 | | 2000 | 6,769,190 | | 1999 | 6,250,100 | | 1998 | 4,607,700 | | 1997 | 4,566,100 | | 1996 | 4,681,700 | | 1995 | 5,123,200 | | 1994 | 4,779,300 | | 1993 | 4,455,100 | | 1992 | 4,324,000 | | 1991 | 4,461,200 | | 1990 | 4,412,200 | | 1989 | 4,686,700 | | 1988 | 4,521,000 | | 1987 | 4,402,700 | | 1986 | 4,223,300 | | 1985 | 3,792,000 | | 1984 | 3,621,900 | | 1983 | 3,378,500 | | 1982 | 3,454,900 | | 1981 | 3,444,600 | | 1980 | 2,161,900 | | 1979 | 1,996,300 | | 1978 | 1,599,200 | | 1977 | 1,567,200 | | 1976 | 1,745,000 | | 1975 | 1,580,400 | | 1974 | 1,126,600 | | 1973 | 936,900 | | 1972 | 913,500 | | 1971 | 818,000 | | 1970 | 657,600 |
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