| Year | Value | | 2022 | 28,097 | | 2021 | 28,003 | | 2020 | 28,016 | | 2019 | 28,310 | | 2018 | 28,600 | | 2017 | 28,472 | | 2016 | 28,094 | | 2015 | 27,539 | | 2014 | 26,885 | | 2013 | 26,127 | | 2012 | 25,280 | | 2011 | 24,268 | | 2010 | 23,187 | | 2009 | 22,165 | | 2008 | 21,112 | | 2007 | 19,913 | | 2006 | 18,578 | | 2005 | 17,211 | | 2004 | 16,107 | | 2003 | 15,595 | | 2002 | 15,177 | | 2001 | 14,495 | | 2000 | 13,795 | | 1999 | 13,028 | | 1998 | 12,082 | | 1997 | 10,694 | | 1996 | 9,698 | | 1995 | 9,268 | | 1994 | 9,038 | | 1993 | 8,908 | | 1992 | 8,374 | | 1991 | 7,722 | | 1990 | 8,588 | | 1989 | 9,590 | | 1988 | 9,221 | | 1987 | 8,883 | | 1986 | 8,546 | | 1985 | 8,197 | | 1984 | 7,831 | | 1983 | 7,640 | | 1982 | 7,472 | | 1981 | 7,181 | | 1980 | 6,964 | | 1979 | 6,814 | | 1978 | 6,715 | | 1977 | 6,659 | | 1976 | 6,636 | | 1975 | 6,637 | | 1974 | 6,561 | | 1973 | 6,404 | | 1972 | 6,260 | | 1971 | 6,123 | | 1970 | 5,992 | | 1969 | 5,864 | | 1968 | 5,736 | | 1967 | 5,604 | | 1966 | 5,469 | | 1965 | 5,335 | | 1964 | 5,201 | | 1963 | 5,063 | | 1962 | 4,928 | | 1961 | 4,805 | | 1960 | 4,697 |
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