| Year | Value | | 2022 | 5,408 | | 2021 | 5,381 | | 2020 | 5,379 | | 2019 | 5,198 | | 2018 | 4,988 | | 2017 | 4,817 | | 2016 | 4,657 | | 2015 | 4,519 | | 2014 | 4,600 | | 2013 | 4,794 | | 2012 | 4,920 | | 2011 | 5,042 | | 2010 | 5,073 | | 2009 | 5,010 | | 2008 | 4,930 | | 2007 | 4,871 | | 2006 | 4,868 | | 2005 | 4,861 | | 2004 | 4,820 | | 2003 | 4,819 | | 2002 | 4,798 | | 2001 | 4,848 | | 2000 | 4,924 | | 1999 | 4,933 | | 1998 | 4,988 | | 1997 | 5,095 | | 1996 | 5,251 | | 1995 | 5,475 | | 1994 | 5,707 | | 1993 | 5,897 | | 1992 | 6,104 | | 1991 | 6,351 | | 1990 | 6,653 | | 1989 | 7,009 | | 1988 | 7,255 | | 1987 | 7,270 | | 1986 | 7,176 | | 1985 | 7,051 | | 1984 | 6,895 | | 1983 | 6,706 | | 1982 | 6,480 | | 1981 | 6,215 | | 1980 | 5,904 | | 1979 | 5,553 | | 1978 | 5,160 | | 1977 | 4,728 | | 1976 | 4,266 | | 1975 | 3,978 | | 1974 | 3,894 | | 1973 | 3,841 | | 1972 | 3,816 | | 1971 | 3,802 | | 1970 | 3,782 | | 1969 | 3,750 | | 1968 | 3,711 | | 1967 | 3,668 | | 1966 | 3,623 | | 1965 | 3,574 | | 1964 | 3,521 | | 1963 | 3,455 | | 1962 | 3,376 | | 1961 | 3,297 | | 1960 | 3,220 |
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