| Year | Value | | 2022 | 19,080 | | 2021 | 18,787 | | 2020 | 18,445 | | 2019 | 18,099 | | 2018 | 17,652 | | 2017 | 17,118 | | 2016 | 16,611 | | 2015 | 16,042 | | 2014 | 15,424 | | 2013 | 14,779 | | 2012 | 14,158 | | 2011 | 13,630 | | 2010 | 13,184 | | 2009 | 12,772 | | 2008 | 12,383 | | 2007 | 11,993 | | 2006 | 11,582 | | 2005 | 11,137 | | 2004 | 10,667 | | 2003 | 10,202 | | 2002 | 9,784 | | 2001 | 9,437 | | 2000 | 9,161 | | 1999 | 8,962 | | 1998 | 8,827 | | 1997 | 8,749 | | 1996 | 8,720 | | 1995 | 8,731 | | 1994 | 8,761 | | 1993 | 8,782 | | 1992 | 8,776 | | 1991 | 8,735 | | 1990 | 8,704 | | 1989 | 8,697 | | 1988 | 8,708 | | 1987 | 8,765 | | 1986 | 8,881 | | 1985 | 9,042 | | 1984 | 9,207 | | 1983 | 9,326 | | 1982 | 9,364 | | 1981 | 9,309 | | 1980 | 9,222 | | 1979 | 9,095 | | 1978 | 8,891 | | 1977 | 8,659 | | 1976 | 8,445 | | 1975 | 8,301 | | 1974 | 8,259 | | 1973 | 8,303 | | 1972 | 8,387 | | 1971 | 8,472 | | 1970 | 8,508 | | 1969 | 8,452 | | 1968 | 8,300 | | 1967 | 8,091 | | 1966 | 7,868 | | 1965 | 7,670 | | 1964 | 7,531 | | 1963 | 7,454 | | 1962 | 7,416 | | 1961 | 7,386 | | 1960 | 7,320 |
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