| Year | Value | | 2022 | 6,461 | | 2021 | 6,629 | | 2020 | 6,839 | | 2019 | 7,032 | | 2018 | 7,205 | | 2017 | 7,391 | | 2016 | 7,595 | | 2015 | 7,813 | | 2014 | 8,053 | | 2013 | 8,284 | | 2012 | 8,456 | | 2011 | 8,523 | | 2010 | 8,461 | | 2009 | 8,325 | | 2008 | 8,191 | | 2007 | 8,087 | | 2006 | 8,033 | | 2005 | 8,055 | | 2004 | 8,145 | | 2003 | 8,274 | | 2002 | 8,393 | | 2001 | 8,433 | | 2000 | 8,373 | | 1999 | 8,271 | | 1998 | 8,193 | | 1997 | 8,167 | | 1996 | 8,196 | | 1995 | 8,241 | | 1994 | 8,222 | | 1993 | 8,110 | | 1992 | 7,934 | | 1991 | 7,726 | | 1990 | 7,528 | | 1989 | 7,399 | | 1988 | 7,357 | | 1987 | 7,374 | | 1986 | 7,426 | | 1985 | 7,481 | | 1984 | 7,523 | | 1983 | 7,516 | | 1982 | 7,433 | | 1981 | 7,296 | | 1980 | 7,155 | | 1979 | 7,032 | | 1978 | 6,908 | | 1977 | 6,758 | | 1976 | 6,567 | | 1975 | 6,338 | | 1974 | 6,093 | | 1973 | 5,841 | | 1972 | 5,581 | | 1971 | 5,322 | | 1970 | 5,061 | | 1969 | 4,842 | | 1968 | 4,692 | | 1967 | 4,579 | | 1966 | 4,494 | | 1965 | 4,434 | | 1964 | 4,395 | | 1963 | 4,373 | | 1962 | 4,362 | | 1961 | 4,361 | | 1960 | 4,360 |
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