| Year | Value | | 2022 | 6,262 | | 2021 | 6,301 | | 2020 | 6,377 | | 2019 | 6,504 | | 2018 | 6,645 | | 2017 | 6,750 | | 2016 | 6,848 | | 2015 | 7,019 | | 2014 | 7,179 | | 2013 | 7,256 | | 2012 | 7,356 | | 2011 | 7,414 | | 2010 | 7,368 | | 2009 | 7,360 | | 2008 | 7,459 | | 2007 | 7,569 | | 2006 | 7,590 | | 2005 | 7,549 | | 2004 | 7,495 | | 2003 | 7,432 | | 2002 | 7,378 | | 2001 | 7,342 | | 2000 | 7,331 | | 1999 | 7,344 | | 1998 | 7,359 | | 1997 | 7,367 | | 1996 | 7,367 | | 1995 | 7,344 | | 1994 | 7,303 | | 1993 | 7,280 | | 1992 | 7,289 | | 1991 | 7,320 | | 1990 | 7,367 | | 1989 | 7,428 | | 1988 | 7,474 | | 1987 | 7,480 | | 1986 | 7,459 | | 1985 | 7,426 | | 1984 | 7,390 | | 1983 | 7,380 | | 1982 | 7,400 | | 1981 | 7,436 | | 1980 | 7,477 | | 1979 | 7,519 | | 1978 | 7,576 | | 1977 | 7,654 | | 1976 | 7,703 | | 1975 | 7,705 | | 1974 | 7,702 | | 1973 | 7,755 | | 1972 | 7,877 | | 1971 | 7,981 | | 1970 | 8,032 | | 1969 | 8,028 | | 1968 | 7,963 | | 1967 | 7,834 | | 1966 | 7,689 | | 1965 | 7,551 | | 1964 | 7,394 | | 1963 | 7,224 | | 1962 | 7,046 | | 1961 | 6,855 | | 1960 | 6,647 |
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