| Year | Value | | 2022 | 6,700 | | 2021 | 6,825 | | 2020 | 6,996 | | 2019 | 7,198 | | 2018 | 7,405 | | 2017 | 7,624 | | 2016 | 7,779 | | 2015 | 7,872 | | 2014 | 7,919 | | 2013 | 7,880 | | 2012 | 7,754 | | 2011 | 7,595 | | 2010 | 7,442 | | 2009 | 7,366 | | 2008 | 7,441 | | 2007 | 7,575 | | 2006 | 7,761 | | 2005 | 7,987 | | 2004 | 8,211 | | 2003 | 8,378 | | 2002 | 8,462 | | 2001 | 8,477 | | 2000 | 8,463 | | 1999 | 8,458 | | 1998 | 8,478 | | 1997 | 8,520 | | 1996 | 8,544 | | 1995 | 8,523 | | 1994 | 8,436 | | 1993 | 8,338 | | 1992 | 8,245 | | 1991 | 8,105 | | 1990 | 7,942 | | 1989 | 7,836 | | 1988 | 7,704 | | 1987 | 7,519 | | 1986 | 7,403 | | 1985 | 7,342 | | 1984 | 7,299 | | 1983 | 7,213 | | 1982 | 7,089 | | 1981 | 6,973 | | 1980 | 6,821 | | 1979 | 6,664 | | 1978 | 6,629 | | 1977 | 6,685 | | 1976 | 6,705 | | 1975 | 6,680 | | 1974 | 6,590 | | 1973 | 6,422 | | 1972 | 6,255 | | 1971 | 6,117 | | 1970 | 6,028 | | 1969 | 6,024 | | 1968 | 6,045 | | 1967 | 6,018 | | 1966 | 5,951 | | 1965 | 5,848 | | 1964 | 5,715 | | 1963 | 5,560 | | 1962 | 5,391 | | 1961 | 5,214 | | 1960 | 5,036 |
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