| Year | Value | | 2022 | 6,905 | | 2021 | 6,535 | | 2020 | 6,211 | | 2019 | 6,025 | | 2018 | 5,943 | | 2017 | 5,933 | | 2016 | 5,960 | | 2015 | 6,006 | | 2014 | 6,061 | | 2013 | 6,109 | | 2012 | 6,136 | | 2011 | 6,173 | | 2010 | 6,228 | | 2009 | 6,267 | | 2008 | 6,269 | | 2007 | 6,230 | | 2006 | 6,139 | | 2005 | 6,013 | | 2004 | 5,885 | | 2003 | 5,773 | | 2002 | 5,696 | | 2001 | 5,644 | | 2000 | 5,607 | | 1999 | 5,588 | | 1998 | 5,576 | | 1997 | 5,549 | | 1996 | 5,496 | | 1995 | 5,413 | | 1994 | 5,303 | | 1993 | 5,177 | | 1992 | 5,043 | | 1991 | 4,920 | | 1990 | 4,816 | | 1989 | 4,712 | | 1988 | 4,595 | | 1987 | 4,461 | | 1986 | 4,303 | | 1985 | 4,125 | | 1984 | 3,942 | | 1983 | 3,780 | | 1982 | 3,653 | | 1981 | 3,586 | | 1980 | 3,566 | | 1979 | 3,552 | | 1978 | 3,541 | | 1977 | 3,532 | | 1976 | 3,474 | | 1975 | 3,363 | | 1974 | 3,267 | | 1973 | 3,270 | | 1972 | 3,347 | | 1971 | 3,394 | | 1970 | 3,403 | | 1969 | 3,387 | | 1968 | 3,365 | | 1967 | 3,354 | | 1966 | 3,382 | | 1965 | 3,425 | | 1964 | 3,445 | | 1963 | 3,440 | | 1962 | 3,398 | | 1961 | 3,342 | | 1960 | 3,274 |
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