| Year | Value | | 2022 | 5,564 | | 2021 | 5,523 | | 2020 | 5,495 | | 2019 | 5,460 | | 2018 | 5,393 | | 2017 | 5,332 | | 2016 | 5,291 | | 2015 | 5,272 | | 2014 | 5,298 | | 2013 | 5,395 | | 2012 | 5,508 | | 2011 | 5,520 | | 2010 | 5,412 | | 2009 | 5,309 | | 2008 | 5,233 | | 2007 | 5,196 | | 2006 | 5,179 | | 2005 | 5,169 | | 2004 | 5,212 | | 2003 | 5,300 | | 2002 | 5,397 | | 2001 | 5,478 | | 2000 | 5,529 | | 1999 | 5,542 | | 1998 | 5,526 | | 1997 | 5,481 | | 1996 | 5,374 | | 1995 | 5,229 | | 1994 | 5,120 | | 1993 | 5,076 | | 1992 | 5,104 | | 1991 | 5,201 | | 1990 | 5,362 | | 1989 | 5,569 | | 1988 | 5,792 | | 1987 | 6,001 | | 1986 | 6,097 | | 1985 | 6,046 | | 1984 | 5,920 | | 1983 | 5,770 | | 1982 | 5,633 | | 1981 | 5,536 | | 1980 | 5,477 | | 1979 | 5,438 | | 1978 | 5,405 | | 1977 | 5,356 | | 1976 | 5,245 | | 1975 | 5,089 | | 1974 | 4,940 | | 1973 | 4,783 | | 1972 | 4,620 | | 1971 | 4,469 | | 1970 | 4,331 | | 1969 | 4,205 | | 1968 | 4,096 | | 1967 | 3,990 | | 1966 | 3,882 | | 1965 | 3,781 | | 1964 | 3,679 | | 1963 | 3,579 | | 1962 | 3,492 | | 1961 | 3,406 | | 1960 | 3,309 |
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