| Year | Value | | 2022 | 8,915 | | 2021 | 8,883 | | 2020 | 8,827 | | 2019 | 8,817 | | 2018 | 8,836 | | 2017 | 8,834 | | 2016 | 8,803 | | 2015 | 8,682 | | 2014 | 8,439 | | 2013 | 8,121 | | 2012 | 7,769 | | 2011 | 7,413 | | 2010 | 7,139 | | 2009 | 6,981 | | 2008 | 6,894 | | 2007 | 6,869 | | 2006 | 6,916 | | 2005 | 7,027 | | 2004 | 7,169 | | 2003 | 7,317 | | 2002 | 7,448 | | 2001 | 7,610 | | 2000 | 7,789 | | 1999 | 7,921 | | 1998 | 8,010 | | 1997 | 8,042 | | 1996 | 8,001 | | 1995 | 7,890 | | 1994 | 7,742 | | 1993 | 7,582 | | 1992 | 7,451 | | 1991 | 7,450 | | 1990 | 7,605 | | 1989 | 7,771 | | 1988 | 7,836 | | 1987 | 7,773 | | 1986 | 7,729 | | 1985 | 7,787 | | 1984 | 7,832 | | 1983 | 7,794 | | 1982 | 7,652 | | 1981 | 7,444 | | 1980 | 7,202 | | 1979 | 6,907 | | 1978 | 6,546 | | 1977 | 6,138 | | 1976 | 5,919 | | 1975 | 5,928 | | 1974 | 5,899 | | 1973 | 5,718 | | 1972 | 5,445 | | 1971 | 5,182 | | 1970 | 4,953 | | 1969 | 4,779 | | 1968 | 4,637 | | 1967 | 4,523 | | 1966 | 4,467 | | 1965 | 4,435 | | 1964 | 4,423 | | 1963 | 4,436 | | 1962 | 4,457 | | 1961 | 4,442 | | 1960 | 4,388 |
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