| Year | Value | | 2022 | 44,036 | | 2021 | 44,372 | | 2020 | 43,986 | | 2019 | 43,236 | | 2018 | 42,267 | | 2017 | 41,312 | | 2016 | 40,520 | | 2015 | 39,716 | | 2014 | 38,728 | | 2013 | 37,692 | | 2012 | 36,678 | | 2011 | 35,701 | | 2010 | 34,895 | | 2009 | 34,037 | | 2008 | 32,817 | | 2007 | 31,104 | | 2006 | 28,930 | | 2005 | 26,606 | | 2004 | 24,588 | | 2003 | 22,956 | | 2002 | 21,461 | | 2001 | 20,177 | | 2000 | 19,151 | | 1999 | 18,229 | | 1998 | 17,441 | | 1997 | 17,054 | | 1996 | 16,891 | | 1995 | 16,813 | | 1994 | 16,796 | | 1993 | 16,715 | | 1992 | 16,526 | | 1991 | 16,114 | | 1990 | 15,683 | | 1989 | 15,386 | | 1988 | 15,262 | | 1987 | 15,486 | | 1986 | 16,076 | | 1985 | 16,816 | | 1984 | 17,393 | | 1983 | 17,604 | | 1982 | 17,488 | | 1981 | 17,006 | | 1980 | 16,225 | | 1979 | 15,282 | | 1978 | 14,388 | | 1977 | 13,746 | | 1976 | 13,275 | | 1975 | 13,004 | | 1974 | 12,883 | | 1973 | 12,826 | | 1972 | 12,750 | | 1971 | 12,580 | | 1970 | 12,291 | | 1969 | 11,924 | | 1968 | 11,519 | | 1967 | 11,086 | | 1966 | 10,665 | | 1965 | 10,292 | | 1964 | 9,959 | | 1963 | 9,658 | | 1962 | 9,351 | | 1961 | 8,962 | | 1960 | 8,723 |
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