| Year | Value | | 2022 | 4,232 | | 2021 | 4,305 | | 2020 | 4,412 | | 2019 | 4,576 | | 2018 | 4,792 | | 2017 | 5,021 | | 2016 | 5,253 | | 2015 | 5,484 | | 2014 | 5,704 | | 2013 | 5,910 | | 2012 | 6,090 | | 2011 | 6,237 | | 2010 | 6,349 | | 2009 | 6,427 | | 2008 | 6,468 | | 2007 | 6,485 | | 2006 | 6,478 | | 2005 | 6,437 | | 2004 | 6,346 | | 2003 | 6,211 | | 2002 | 6,041 | | 2001 | 5,848 | | 2000 | 5,664 | | 1999 | 5,521 | | 1998 | 5,421 | | 1997 | 5,350 | | 1996 | 5,302 | | 1995 | 5,275 | | 1994 | 5,262 | | 1993 | 5,227 | | 1992 | 5,143 | | 1991 | 4,978 | | 1990 | 4,697 | | 1989 | 4,355 | | 1988 | 4,040 | | 1987 | 3,759 | | 1986 | 3,525 | | 1985 | 3,388 | | 1984 | 3,317 | | 1983 | 3,233 | | 1982 | 3,121 | | 1981 | 2,973 | | 1980 | 2,809 | | 1979 | 2,703 | | 1978 | 2,685 | | 1977 | 2,724 | | 1976 | 2,775 | | 1975 | 2,836 | | 1974 | 2,909 | | 1973 | 2,991 | | 1972 | 3,079 | | 1971 | 3,150 | | 1970 | 3,212 | | 1969 | 3,347 | | 1968 | 3,482 | | 1967 | 3,486 | | 1966 | 3,366 | | 1965 | 3,167 | | 1964 | 2,965 | | 1963 | 2,815 | | 1962 | 2,735 | | 1961 | 2,719 | | 1960 | 2,742 |
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