| Year | Value | | 2022 | 4,352 | | 2021 | 4,283 | | 2020 | 4,277 | | 2019 | 4,342 | | 2018 | 4,428 | | 2017 | 4,523 | | 2016 | 4,634 | | 2015 | 4,715 | | 2014 | 4,768 | | 2013 | 4,849 | | 2012 | 4,963 | | 2011 | 5,112 | | 2010 | 5,326 | | 2009 | 5,596 | | 2008 | 5,864 | | 2007 | 6,095 | | 2006 | 6,262 | | 2005 | 6,344 | | 2004 | 6,330 | | 2003 | 6,221 | | 2002 | 6,084 | | 2001 | 5,905 | | 2000 | 5,605 | | 1999 | 5,248 | | 1998 | 4,925 | | 1997 | 4,690 | | 1996 | 4,591 | | 1995 | 4,576 | | 1994 | 4,630 | | 1993 | 4,734 | | 1992 | 4,796 | | 1991 | 4,772 | | 1990 | 4,738 | | 1989 | 4,793 | | 1988 | 4,951 | | 1987 | 5,201 | | 1986 | 5,496 | | 1985 | 5,756 | | 1984 | 5,926 | | 1983 | 6,002 | | 1982 | 6,008 | | 1981 | 5,990 | | 1980 | 6,056 | | 1979 | 6,173 | | 1978 | 6,259 | | 1977 | 6,339 | | 1976 | 6,405 | | 1975 | 6,433 | | 1974 | 6,401 | | 1973 | 6,300 | | 1972 | 6,130 | | 1971 | 5,907 | | 1970 | 5,650 | | 1969 | 5,386 | | 1968 | 5,159 | | 1967 | 4,983 | | 1966 | 4,841 | | 1965 | 4,716 | | 1964 | 4,601 | | 1963 | 4,498 | | 1962 | 4,419 | | 1961 | 4,374 | | 1960 | 4,365 |
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