| Year | Value | | 2022 | 18,957 | | 2021 | 18,228 | | 2020 | 17,573 | | 2019 | 16,885 | | 2018 | 16,222 | | 2017 | 15,586 | | 2016 | 15,012 | | 2015 | 14,430 | | 2014 | 13,849 | | 2013 | 13,291 | | 2012 | 12,758 | | 2011 | 12,246 | | 2010 | 11,742 | | 2009 | 11,195 | | 2008 | 10,687 | | 2007 | 10,252 | | 2006 | 9,819 | | 2005 | 9,364 | | 2004 | 8,904 | | 2003 | 8,543 | | 2002 | 8,208 | | 2001 | 7,884 | | 2000 | 7,648 | | 1999 | 7,503 | | 1998 | 7,374 | | 1997 | 7,242 | | 1996 | 7,115 | | 1995 | 6,965 | | 1994 | 6,841 | | 1993 | 6,732 | | 1992 | 6,649 | | 1991 | 6,565 | | 1990 | 6,499 | | 1989 | 6,435 | | 1988 | 6,336 | | 1987 | 6,211 | | 1986 | 6,055 | | 1985 | 5,898 | | 1984 | 5,743 | | 1983 | 5,574 | | 1982 | 5,371 | | 1981 | 5,157 | | 1980 | 4,941 | | 1979 | 4,710 | | 1978 | 4,502 | | 1977 | 4,335 | | 1976 | 4,195 | | 1975 | 4,093 | | 1974 | 4,046 | | 1973 | 4,067 | | 1972 | 4,154 | | 1971 | 4,268 | | 1970 | 4,388 | | 1969 | 4,259 | | 1968 | 3,898 | | 1967 | 3,589 | | 1966 | 3,321 | | 1965 | 3,083 | | 1964 | 2,867 | | 1963 | 2,656 | | 1962 | 2,451 | | 1961 | 2,271 | | 1960 | 2,139 |
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