| Year | Value | | 2022 | 4,023 | | 2021 | 3,998 | | 2020 | 4,047 | | 2019 | 4,107 | | 2018 | 4,286 | | 2017 | 4,620 | | 2016 | 4,829 | | 2015 | 4,918 | | 2014 | 4,968 | | 2013 | 5,016 | | 2012 | 5,092 | | 2011 | 5,206 | | 2010 | 5,294 | | 2009 | 5,349 | | 2008 | 5,365 | | 2007 | 5,284 | | 2006 | 5,134 | | 2005 | 4,971 | | 2004 | 4,874 | | 2003 | 4,865 | | 2002 | 4,857 | | 2001 | 4,961 | | 2000 | 5,268 | | 1999 | 5,619 | | 1998 | 5,982 | | 1997 | 6,271 | | 1996 | 6,444 | | 1995 | 6,593 | | 1994 | 6,758 | | 1993 | 6,910 | | 1992 | 7,021 | | 1991 | 7,135 | | 1990 | 7,241 | | 1989 | 7,343 | | 1988 | 7,460 | | 1987 | 7,553 | | 1986 | 7,584 | | 1985 | 7,552 | | 1984 | 7,476 | | 1983 | 7,404 | | 1982 | 7,328 | | 1981 | 7,251 | | 1980 | 7,241 | | 1979 | 7,275 | | 1978 | 7,373 | | 1977 | 7,536 | | 1976 | 7,666 | | 1975 | 7,818 | | 1974 | 7,995 | | 1973 | 8,181 | | 1972 | 8,514 | | 1971 | 8,806 | | 1970 | 8,955 | | 1969 | 9,094 | | 1968 | 9,194 | | 1967 | 9,278 | | 1966 | 9,391 | | 1965 | 9,488 | | 1964 | 9,577 | | 1963 | 9,692 | | 1962 | 9,757 | | 1961 | 9,799 | | 1960 | 9,844 |
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