| Year | Value | | 2022 | 17,686 | | 2021 | 17,510 | | 2020 | 17,381 | | 2019 | 17,266 | | 2018 | 17,157 | | 2017 | 17,002 | | 2016 | 16,721 | | 2015 | 16,301 | | 2014 | 15,766 | | 2013 | 15,119 | | 2012 | 14,389 | | 2011 | 13,640 | | 2010 | 12,909 | | 2009 | 12,209 | | 2008 | 11,588 | | 2007 | 11,105 | | 2006 | 10,739 | | 2005 | 10,428 | | 2004 | 10,135 | | 2003 | 9,642 | | 2002 | 8,922 | | 2001 | 8,215 | | 2000 | 7,608 | | 1999 | 7,115 | | 1998 | 6,729 | | 1997 | 6,417 | | 1996 | 6,127 | | 1995 | 5,840 | | 1994 | 5,696 | | 1993 | 5,736 | | 1992 | 5,823 | | 1991 | 5,923 | | 1990 | 6,039 | | 1989 | 6,143 | | 1988 | 6,215 | | 1987 | 6,284 | | 1986 | 6,340 | | 1985 | 6,346 | | 1984 | 6,318 | | 1983 | 6,272 | | 1982 | 6,218 | | 1981 | 6,162 | | 1980 | 6,118 | | 1979 | 6,078 | | 1978 | 6,031 | | 1977 | 5,968 | | 1976 | 5,864 | | 1975 | 5,700 | | 1974 | 5,489 | | 1973 | 5,261 | | 1972 | 5,048 | | 1971 | 4,861 | | 1970 | 4,746 | | 1969 | 4,741 | | 1968 | 4,801 | | 1967 | 4,860 | | 1966 | 4,839 | | 1965 | 4,679 | | 1964 | 4,412 | | 1963 | 4,191 | | 1962 | 4,094 | | 1961 | 4,036 | | 1960 | 3,962 |
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