| Year | Value | | 2018 | 831,838 | | 2017 | 786,595 | | 2016 | 743,900 | | 2015 | 706,743 | | 2014 | 669,083 | | 2013 | 636,472 | | 2012 | 608,306 | | 2011 | 583,352 | | 2010 | 560,811 | | 2009 | 539,089 | | 2008 | 520,434 | | 2007 | 504,446 | | 2006 | 490,525 | | 2005 | 478,153 | | 2004 | 464,360 | | 2003 | 451,812 | | 2002 | 440,113 | | 2001 | 428,635 | | 2000 | 416,911 | | 1999 | 403,648 | | 1998 | 389,912 | | 1997 | 376,065 | | 1996 | 362,762 | | 1995 | 350,390 | | 1994 | 336,468 | | 1993 | 323,148 | | 1992 | 310,524 | | 1991 | 298,637 | | 1990 | 287,492 | | 1989 | 275,455 | | 1988 | 264,210 | | 1987 | 253,938 | | 1986 | 244,939 | | 1985 | 237,419 | | 1984 | 230,398 | | 1983 | 225,105 | | 1982 | 220,957 | | 1981 | 216,978 | | 1980 | 212,482 | | 1979 | 205,400 | | 1978 | 197,376 | | 1977 | 188,831 | | 1976 | 180,648 | | 1975 | 173,470 | | 1974 | 166,453 | | 1973 | 160,532 | | 1972 | 155,582 | | 1971 | 151,246 | | 1970 | 147,277 | | 1969 | 142,879 | | 1968 | 139,059 | | 1967 | 135,686 | | 1966 | 132,591 | | 1965 | 129,653 | | 1964 | 125,620 | | 1963 | 121,512 | | 1962 | 117,472 | | 1961 | 113,819 | | 1960 | 110,811 |
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