| Year | Value | | 2022 | 4,073 | | 2021 | 4,192 | | 2020 | 4,316 | | 2019 | 4,446 | | 2018 | 4,579 | | 2017 | 4,717 | | 2016 | 4,860 | | 2015 | 5,009 | | 2014 | 5,164 | | 2013 | 5,326 | | 2012 | 5,497 | | 2011 | 5,673 | | 2010 | 5,858 | | 2009 | 6,050 | | 2008 | 6,245 | | 2007 | 6,443 | | 2006 | 6,653 | | 2005 | 6,872 | | 2004 | 7,093 | | 2003 | 7,323 | | 2002 | 7,557 | | 2001 | 7,800 | | 2000 | 8,055 | | 1999 | 8,440 | | 1998 | 8,888 | | 1997 | 9,347 | | 1996 | 9,818 | | 1995 | 10,311 | | 1994 | 10,803 | | 1993 | 11,288 | | 1992 | 11,776 | | 1991 | 12,278 | | 1990 | 12,803 | | 1989 | 13,076 | | 1988 | 13,722 | | 1987 | 14,403 | | 1986 | 15,109 | | 1985 | 15,839 | | 1984 | 16,585 | | 1983 | 17,343 | | 1982 | 18,121 | | 1981 | 18,938 | | 1980 | 19,781 | | 1979 | 19,979 | | 1978 | 20,838 | | 1977 | 21,159 | | 1976 | 22,803 | | 1975 | 23,390 | | 1974 | 23,230 | | 1973 | 22,654 | | 1972 | 21,414 | | 1971 | 20,729 | | 1970 | 19,302 | | 1969 | 19,068 | | 1968 | 18,303 | | 1967 | 16,756 | | 1966 | 16,361 | | 1965 | 15,974 | | 1964 | 15,524 | | 1963 | 15,680 | | 1962 | 14,266 | | 1961 | 14,453 | | 1960 | 14,145 |
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