| Year | Value | | 2022 | 5,363 | | 2021 | 5,585 | | 2020 | 5,791 | | 2019 | 6,194 | | 2018 | 6,151 | | 2017 | 5,728 | | 2016 | 5,690 | | 2015 | 5,689 | | 2014 | 5,719 | | 2013 | 5,728 | | 2012 | 5,676 | | 2011 | 5,645 | | 2010 | 5,544 | | 2009 | 5,385 | | 2008 | 5,328 | | 2007 | 5,335 | | 2006 | 5,383 | | 2005 | 5,429 | | 2004 | 5,358 | | 2003 | 5,204 | | 2002 | 4,986 | | 2001 | 4,818 | | 2000 | 4,875 | | 1999 | 5,026 | | 1998 | 5,179 | | 1997 | 5,248 | | 1996 | 5,221 | | 1995 | 5,200 | | 1994 | 5,231 | | 1993 | 5,303 | | 1992 | 5,404 | | 1991 | 5,555 | | 1990 | 5,761 | | 1989 | 6,052 | | 1988 | 6,438 | | 1987 | 6,870 | | 1986 | 7,303 | | 1985 | 7,699 | | 1984 | 8,030 | | 1983 | 8,323 | | 1982 | 8,555 | | 1981 | 8,727 | | 1980 | 8,913 | | 1979 | 9,069 | | 1978 | 9,202 | | 1977 | 9,298 | | 1976 | 9,242 | | 1975 | 9,104 | | 1974 | 8,888 | | 1973 | 8,603 | | 1972 | 8,416 | | 1971 | 8,130 | | 1970 | 7,727 | | 1969 | 7,406 | | 1968 | 7,139 | | 1967 | 6,927 | | 1966 | 6,777 | | 1965 | 6,634 | | 1964 | 6,438 | | 1963 | 6,197 | | 1962 | 5,917 | | 1961 | 5,638 | | 1960 | 5,458 |
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