| Year | Value | | 2022 | 13,659 | | 2021 | 13,507 | | 2020 | 13,382 | | 2019 | 13,219 | | 2018 | 13,021 | | 2017 | 12,818 | | 2016 | 12,594 | | 2015 | 12,344 | | 2014 | 12,062 | | 2013 | 11,744 | | 2012 | 11,397 | | 2011 | 11,039 | | 2010 | 10,690 | | 2009 | 10,364 | | 2008 | 10,066 | | 2007 | 9,799 | | 2006 | 9,574 | | 2005 | 9,399 | | 2004 | 9,267 | | 2003 | 9,179 | | 2002 | 9,138 | | 2001 | 9,140 | | 2000 | 9,180 | | 1999 | 9,269 | | 1998 | 9,402 | | 1997 | 9,552 | | 1996 | 9,696 | | 1995 | 9,821 | | 1994 | 9,898 | | 1993 | 9,906 | | 1992 | 9,886 | | 1991 | 9,898 | | 1990 | 9,852 | | 1989 | 9,710 | | 1988 | 9,562 | | 1987 | 9,415 | | 1986 | 9,276 | | 1985 | 9,144 | | 1984 | 9,031 | | 1983 | 8,941 | | 1982 | 8,871 | | 1981 | 8,817 | | 1980 | 8,764 | | 1979 | 8,814 | | 1978 | 9,041 | | 1977 | 9,263 | | 1976 | 9,327 | | 1975 | 9,229 | | 1974 | 8,960 | | 1973 | 8,634 | | 1972 | 8,326 | | 1971 | 8,020 | | 1970 | 7,676 | | 1969 | 7,299 | | 1968 | 6,879 | | 1967 | 6,419 | | 1966 | 6,077 | | 1965 | 5,922 | | 1964 | 5,920 | | 1963 | 6,003 | | 1962 | 6,108 | | 1961 | 6,174 | | 1960 | 6,149 |
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