| Year | Value | | 2022 | 5,158 | | 2021 | 5,311 | | 2020 | 5,545 | | 2019 | 5,979 | | 2018 | 6,047 | | 2017 | 5,832 | | 2016 | 5,832 | | 2015 | 5,652 | | 2014 | 5,340 | | 2013 | 4,968 | | 2012 | 4,605 | | 2011 | 4,366 | | 2010 | 4,342 | | 2009 | 4,485 | | 2008 | 4,653 | | 2007 | 4,727 | | 2006 | 4,668 | | 2005 | 4,480 | | 2004 | 4,234 | | 2003 | 4,019 | | 2002 | 3,799 | | 2001 | 3,678 | | 2000 | 3,773 | | 1999 | 3,975 | | 1998 | 4,220 | | 1997 | 4,436 | | 1996 | 4,585 | | 1995 | 4,743 | | 1994 | 4,962 | | 1993 | 5,209 | | 1992 | 5,487 | | 1991 | 5,837 | | 1990 | 6,215 | | 1989 | 6,600 | | 1988 | 7,002 | | 1987 | 7,376 | | 1986 | 7,671 | | 1985 | 7,876 | | 1984 | 7,996 | | 1983 | 8,057 | | 1982 | 8,038 | | 1981 | 7,918 | | 1980 | 7,765 | | 1979 | 7,580 | | 1978 | 7,400 | | 1977 | 7,238 | | 1976 | 7,023 | | 1975 | 6,815 | | 1974 | 6,611 | | 1973 | 6,416 | | 1972 | 6,340 | | 1971 | 6,280 | | 1970 | 6,183 | | 1969 | 6,092 | | 1968 | 5,950 | | 1967 | 5,758 | | 1966 | 5,556 | | 1965 | 5,338 | | 1964 | 5,109 | | 1963 | 4,920 | | 1962 | 4,769 | | 1961 | 4,659 | | 1960 | 4,628 |
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