| Year | Value | | 2022 | 5,248 | | 2021 | 5,298 | | 2020 | 5,336 | | 2019 | 5,364 | | 2018 | 5,381 | | 2017 | 5,389 | | 2016 | 5,392 | | 2015 | 5,389 | | 2014 | 5,494 | | 2013 | 5,702 | | 2012 | 5,896 | | 2011 | 6,072 | | 2010 | 6,250 | | 2009 | 6,332 | | 2008 | 6,347 | | 2007 | 6,430 | | 2006 | 6,571 | | 2005 | 6,765 | | 2004 | 7,039 | | 2003 | 7,369 | | 2002 | 7,698 | | 2001 | 8,012 | | 2000 | 8,241 | | 1999 | 8,345 | | 1998 | 8,440 | | 1997 | 8,618 | | 1996 | 8,846 | | 1995 | 9,090 | | 1994 | 9,330 | | 1993 | 9,555 | | 1992 | 9,749 | | 1991 | 9,888 | | 1990 | 9,993 | | 1989 | 10,096 | | 1988 | 10,191 | | 1987 | 10,274 | | 1986 | 10,342 | | 1985 | 10,400 | | 1984 | 10,450 | | 1983 | 10,486 | | 1982 | 10,496 | | 1981 | 10,474 | | 1980 | 10,398 | | 1979 | 10,232 | | 1978 | 10,007 | | 1977 | 9,775 | | 1976 | 9,557 | | 1975 | 9,362 | | 1974 | 9,242 | | 1973 | 9,213 | | 1972 | 9,240 | | 1971 | 9,304 | | 1970 | 9,384 | | 1969 | 9,446 | | 1968 | 9,480 | | 1967 | 9,514 | | 1966 | 9,545 | | 1965 | 9,577 | | 1964 | 9,594 | | 1963 | 9,566 | | 1962 | 9,469 | | 1961 | 9,291 | | 1960 | 9,038 |
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