| Year | Value | | 2022 | 26,550 | | 2021 | 25,520 | | 2020 | 24,371 | | 2019 | 23,183 | | 2018 | 22,055 | | 2017 | 21,062 | | 2016 | 20,235 | | 2015 | 19,539 | | 2014 | 18,900 | | 2013 | 18,277 | | 2012 | 17,651 | | 2011 | 17,026 | | 2010 | 16,426 | | 2009 | 15,881 | | 2008 | 15,425 | | 2007 | 15,070 | | 2006 | 14,798 | | 2005 | 14,578 | | 2004 | 14,367 | | 2003 | 14,214 | | 2002 | 14,073 | | 2001 | 13,842 | | 2000 | 13,575 | | 1999 | 13,326 | | 1998 | 13,090 | | 1997 | 12,832 | | 1996 | 12,560 | | 1995 | 12,273 | | 1994 | 11,962 | | 1993 | 11,625 | | 1992 | 11,258 | | 1991 | 10,860 | | 1990 | 10,436 | | 1989 | 9,910 | | 1988 | 9,307 | | 1987 | 8,785 | | 1986 | 8,392 | | 1985 | 8,096 | | 1984 | 7,953 | | 1983 | 7,953 | | 1982 | 7,948 | | 1981 | 7,875 | | 1980 | 7,754 | | 1979 | 7,631 | | 1978 | 7,517 | | 1977 | 7,398 | | 1976 | 7,267 | | 1975 | 7,125 | | 1974 | 6,966 | | 1973 | 6,790 | | 1972 | 6,609 | | 1971 | 6,426 | | 1970 | 6,249 | | 1969 | 6,083 | | 1968 | 5,928 | | 1967 | 5,783 | | 1966 | 5,684 | | 1965 | 5,634 | | 1964 | 5,601 | | 1963 | 5,583 | | 1962 | 5,576 | | 1961 | 5,578 | | 1960 | 5,589 |
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