| Year | Value | | 2022 | 6,280 | | 2021 | 6,301 | | 2020 | 6,314 | | 2019 | 6,324 | | 2018 | 6,324 | | 2017 | 6,307 | | 2016 | 6,286 | | 2015 | 6,257 | | 2014 | 6,196 | | 2013 | 6,104 | | 2012 | 5,990 | | 2011 | 5,842 | | 2010 | 5,657 | | 2009 | 5,452 | | 2008 | 5,240 | | 2007 | 5,016 | | 2006 | 4,774 | | 2005 | 4,520 | | 2004 | 4,246 | | 2003 | 3,960 | | 2002 | 3,707 | | 2001 | 3,515 | | 2000 | 3,372 | | 1999 | 3,261 | | 1998 | 3,171 | | 1997 | 3,079 | | 1996 | 2,973 | | 1995 | 2,867 | | 1994 | 2,765 | | 1993 | 2,665 | | 1992 | 2,569 | | 1991 | 2,487 | | 1990 | 2,418 | | 1989 | 2,347 | | 1988 | 2,271 | | 1987 | 2,197 | | 1986 | 2,132 | | 1985 | 2,072 | | 1984 | 2,015 | | 1983 | 1,971 | | 1982 | 1,939 | | 1981 | 1,912 | | 1980 | 1,907 | | 1979 | 1,922 | | 1978 | 1,943 | | 1977 | 1,968 | | 1976 | 1,995 | | 1975 | 2,017 | | 1974 | 2,034 | | 1973 | 2,047 | | 1972 | 2,053 | | 1971 | 2,053 | | 1970 | 2,046 | | 1969 | 2,032 | | 1968 | 2,019 | | 1967 | 2,000 | | 1966 | 1,979 | | 1965 | 1,957 | | 1964 | 1,938 | | 1963 | 1,921 | | 1962 | 1,906 | | 1961 | 1,891 | | 1960 | 1,874 |
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