| Year | Value | | 2022 | 4,888 | | 2021 | 5,106 | | 2020 | 5,323 | | 2019 | 5,432 | | 2018 | 5,747 | | 2017 | 6,182 | | 2016 | 6,318 | | 2015 | 6,449 | | 2014 | 6,599 | | 2013 | 6,760 | | 2012 | 6,922 | | 2011 | 7,030 | | 2010 | 6,997 | | 2009 | 6,920 | | 2008 | 6,858 | | 2007 | 6,728 | | 2006 | 6,528 | | 2005 | 6,262 | | 2004 | 5,963 | | 2003 | 5,693 | | 2002 | 5,410 | | 2001 | 5,236 | | 2000 | 5,246 | | 1999 | 5,272 | | 1998 | 5,286 | | 1997 | 5,241 | | 1996 | 5,127 | | 1995 | 5,025 | | 1994 | 4,954 | | 1993 | 4,872 | | 1992 | 4,745 | | 1991 | 4,599 | | 1990 | 4,429 | | 1989 | 4,261 | | 1988 | 4,131 | | 1987 | 4,033 | | 1986 | 3,958 | | 1985 | 3,904 | | 1984 | 3,859 | | 1983 | 3,821 | | 1982 | 3,764 | | 1981 | 3,679 | | 1980 | 3,601 | | 1979 | 3,512 | | 1978 | 3,425 | | 1977 | 3,356 | | 1976 | 3,270 | | 1975 | 3,189 | | 1974 | 3,110 | | 1973 | 3,031 | | 1972 | 3,024 | | 1971 | 3,020 | | 1970 | 2,980 | | 1969 | 2,963 | | 1968 | 2,952 | | 1967 | 2,941 | | 1966 | 2,935 | | 1965 | 2,915 | | 1964 | 2,863 | | 1963 | 2,787 | | 1962 | 2,696 | | 1961 | 2,605 | | 1960 | 2,569 |
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