| Year | Value | | 2022 | 6,315 | | 2021 | 6,147 | | 2020 | 6,001 | | 2019 | 5,948 | | 2018 | 5,967 | | 2017 | 5,946 | | 2016 | 5,823 | | 2015 | 5,645 | | 2014 | 5,434 | | 2013 | 5,222 | | 2012 | 5,076 | | 2011 | 4,965 | | 2010 | 4,891 | | 2009 | 4,895 | | 2008 | 4,920 | | 2007 | 4,952 | | 2006 | 5,022 | | 2005 | 5,016 | | 2004 | 4,891 | | 2003 | 4,715 | | 2002 | 4,441 | | 2001 | 4,090 | | 2000 | 3,873 | | 1999 | 3,786 | | 1998 | 3,717 | | 1997 | 3,710 | | 1996 | 3,759 | | 1995 | 3,780 | | 1994 | 3,754 | | 1993 | 3,715 | | 1992 | 3,664 | | 1991 | 3,606 | | 1990 | 3,593 | | 1989 | 3,599 | | 1988 | 3,593 | | 1987 | 3,602 | | 1986 | 3,618 | | 1985 | 3,630 | | 1984 | 3,624 | | 1983 | 3,614 | | 1982 | 3,638 | | 1981 | 3,705 | | 1980 | 3,758 | | 1979 | 3,717 | | 1978 | 3,569 | | 1977 | 3,385 | | 1976 | 3,275 | | 1975 | 3,325 | | 1974 | 3,470 | | 1973 | 3,628 | | 1972 | 3,778 | | 1971 | 3,903 | | 1970 | 3,968 | | 1969 | 3,985 | | 1968 | 3,991 | | 1967 | 3,964 | | 1966 | 3,921 | | 1965 | 3,882 | | 1964 | 3,852 | | 1963 | 3,801 | | 1962 | 3,730 | | 1961 | 3,692 | | 1960 | 3,718 |
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