| Year | Value | | 2022 | 3,509 | | 2021 | 3,584 | | 2020 | 3,627 | | 2019 | 3,671 | | 2018 | 3,716 | | 2017 | 3,715 | | 2016 | 3,669 | | 2015 | 3,614 | | 2014 | 3,579 | | 2013 | 3,549 | | 2012 | 3,511 | | 2011 | 3,472 | | 2010 | 3,413 | | 2009 | 3,339 | | 2008 | 3,276 | | 2007 | 3,205 | | 2006 | 3,127 | | 2005 | 3,073 | | 2004 | 3,030 | | 2003 | 2,973 | | 2002 | 2,935 | | 2001 | 2,934 | | 2000 | 2,925 | | 1999 | 2,896 | | 1998 | 2,888 | | 1997 | 2,900 | | 1996 | 2,919 | | 1995 | 2,954 | | 1994 | 3,003 | | 1993 | 3,050 | | 1992 | 3,078 | | 1991 | 3,076 | | 1990 | 3,135 | | 1989 | 3,258 | | 1988 | 3,368 | | 1987 | 3,473 | | 1986 | 3,570 | | 1985 | 3,655 | | 1984 | 3,721 | | 1983 | 3,736 | | 1982 | 3,696 | | 1981 | 3,618 | | 1980 | 3,493 | | 1979 | 3,331 | | 1978 | 3,148 | | 1977 | 2,960 | | 1976 | 2,788 | | 1975 | 2,656 | | 1974 | 2,579 | | 1973 | 2,547 | | 1972 | 2,541 | | 1971 | 2,533 | | 1970 | 2,489 | | 1969 | 2,419 | | 1968 | 2,364 | | 1967 | 2,345 | | 1966 | 2,365 | | 1965 | 2,421 | | 1964 | 2,504 | | 1963 | 2,557 | | 1962 | 2,563 | | 1961 | 2,550 | | 1960 | 2,490 |
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