| Year | Value | | 2022 | 6,333 | | 2021 | 6,218 | | 2020 | 6,059 | | 2019 | 5,868 | | 2018 | 5,713 | | 2017 | 5,630 | | 2016 | 5,669 | | 2015 | 5,803 | | 2014 | 5,960 | | 2013 | 6,125 | | 2012 | 6,258 | | 2011 | 6,362 | | 2010 | 6,425 | | 2009 | 6,476 | | 2008 | 6,506 | | 2007 | 6,484 | | 2006 | 6,404 | | 2005 | 6,253 | | 2004 | 6,072 | | 2003 | 5,911 | | 2002 | 5,784 | | 2001 | 5,647 | | 2000 | 5,505 | | 1999 | 5,389 | | 1998 | 5,295 | | 1997 | 5,211 | | 1996 | 5,146 | | 1995 | 5,128 | | 1994 | 5,169 | | 1993 | 5,271 | | 1992 | 5,414 | | 1991 | 5,490 | | 1990 | 5,411 | | 1989 | 5,226 | | 1988 | 4,969 | | 1987 | 4,642 | | 1986 | 4,321 | | 1985 | 4,130 | | 1984 | 4,076 | | 1983 | 4,067 | | 1982 | 4,083 | | 1981 | 4,120 | | 1980 | 4,147 | | 1979 | 4,132 | | 1978 | 4,076 | | 1977 | 4,008 | | 1976 | 3,925 | | 1975 | 3,831 | | 1974 | 3,735 | | 1973 | 3,638 | | 1972 | 3,564 | | 1971 | 3,554 | | 1970 | 3,581 | | 1969 | 3,629 | | 1968 | 3,700 | | 1967 | 3,754 | | 1966 | 3,757 | | 1965 | 3,734 | | 1964 | 3,679 | | 1963 | 3,567 | | 1962 | 3,423 | | 1961 | 3,284 | | 1960 | 3,176 |
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