| Year | Value | | 2022 | 18,710 | | 2021 | 18,089 | | 2020 | 17,623 | | 2019 | 17,033 | | 2018 | 16,378 | | 2017 | 15,837 | | 2016 | 15,395 | | 2015 | 15,077 | | 2014 | 14,871 | | 2013 | 14,660 | | 2012 | 14,360 | | 2011 | 13,983 | | 2010 | 13,565 | | 2009 | 13,115 | | 2008 | 12,643 | | 2007 | 12,175 | | 2006 | 11,760 | | 2005 | 11,404 | | 2004 | 11,083 | | 2003 | 10,806 | | 2002 | 10,556 | | 2001 | 10,291 | | 2000 | 10,012 | | 1999 | 9,742 | | 1998 | 9,488 | | 1997 | 9,263 | | 1996 | 9,079 | | 1995 | 8,943 | | 1994 | 8,790 | | 1993 | 8,592 | | 1992 | 8,391 | | 1991 | 8,217 | | 1990 | 8,038 | | 1989 | 7,822 | | 1988 | 7,595 | | 1987 | 7,373 | | 1986 | 7,131 | | 1985 | 6,866 | | 1984 | 6,589 | | 1983 | 6,311 | | 1982 | 6,041 | | 1981 | 5,813 | | 1980 | 5,618 | | 1979 | 5,405 | | 1978 | 5,220 | | 1977 | 5,111 | | 1976 | 5,051 | | 1975 | 5,017 | | 1974 | 4,948 | | 1973 | 4,821 | | 1972 | 4,640 | | 1971 | 4,462 | | 1970 | 4,315 | | 1969 | 4,229 | | 1968 | 4,166 | | 1967 | 4,088 | | 1966 | 3,959 | | 1965 | 3,800 | | 1964 | 3,674 | | 1963 | 3,573 | | 1962 | 3,479 | | 1961 | 3,402 | | 1960 | 3,366 |
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