| Year | Value | | 2022 | 16,649 | | 2021 | 16,498 | | 2020 | 16,259 | | 2019 | 15,859 | | 2018 | 15,179 | | 2017 | 14,403 | | 2016 | 13,680 | | 2015 | 12,623 | | 2014 | 11,373 | | 2013 | 10,537 | | 2012 | 9,997 | | 2011 | 9,747 | | 2010 | 10,178 | | 2009 | 11,004 | | 2008 | 11,745 | | 2007 | 12,358 | | 2006 | 12,755 | | 2005 | 12,872 | | 2004 | 12,761 | | 2003 | 12,461 | | 2002 | 12,062 | | 2001 | 11,726 | | 2000 | 11,448 | | 1999 | 11,286 | | 1998 | 11,200 | | 1997 | 11,076 | | 1996 | 10,684 | | 1995 | 9,975 | | 1994 | 9,061 | | 1993 | 8,089 | | 1992 | 7,211 | | 1991 | 6,568 | | 1990 | 6,149 | | 1989 | 5,852 | | 1988 | 5,622 | | 1987 | 5,470 | | 1986 | 5,471 | | 1985 | 5,722 | | 1984 | 6,209 | | 1983 | 6,811 | | 1982 | 7,378 | | 1981 | 7,757 | | 1980 | 7,868 | | 1979 | 7,768 | | 1978 | 7,570 | | 1977 | 7,347 | | 1976 | 7,116 | | 1975 | 6,851 | | 1974 | 6,520 | | 1973 | 6,140 | | 1972 | 5,763 | | 1971 | 5,470 | | 1970 | 5,325 | | 1969 | 5,351 | | 1968 | 5,503 | | 1967 | 5,697 | | 1966 | 5,845 | | 1965 | 5,874 | | 1964 | 5,760 | | 1963 | 5,532 | | 1962 | 5,252 | | 1961 | 4,986 | | 1960 | 4,786 |
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