| Year | Value | | 2022 | 8,413 | | 2021 | 8,375 | | 2020 | 8,190 | | 2019 | 7,903 | | 2018 | 7,569 | | 2017 | 7,202 | | 2016 | 6,835 | | 2015 | 6,557 | | 2014 | 6,405 | | 2013 | 6,336 | | 2012 | 6,336 | | 2011 | 6,365 | | 2010 | 6,407 | | 2009 | 6,470 | | 2008 | 6,543 | | 2007 | 6,614 | | 2006 | 6,699 | | 2005 | 6,801 | | 2004 | 6,890 | | 2003 | 6,938 | | 2002 | 6,933 | | 2001 | 6,886 | | 2000 | 6,787 | | 1999 | 6,640 | | 1998 | 6,482 | | 1997 | 6,344 | | 1996 | 6,253 | | 1995 | 6,211 | | 1994 | 6,193 | | 1993 | 6,181 | | 1992 | 6,159 | | 1991 | 6,134 | | 1990 | 6,116 | | 1989 | 6,064 | | 1988 | 5,963 | | 1987 | 5,838 | | 1986 | 5,760 | | 1985 | 5,704 | | 1984 | 5,570 | | 1983 | 5,361 | | 1982 | 5,100 | | 1981 | 4,848 | | 1980 | 4,635 | | 1979 | 4,453 | | 1978 | 4,311 | | 1977 | 4,207 | | 1976 | 4,144 | | 1975 | 4,042 | | 1974 | 3,852 | | 1973 | 3,673 | | 1972 | 3,581 | | 1971 | 3,567 | | 1970 | 3,609 | | 1969 | 3,688 | | 1968 | 3,778 | | 1967 | 3,847 | | 1966 | 3,896 | | 1965 | 3,928 | | 1964 | 3,942 | | 1963 | 3,957 | | 1962 | 3,974 | | 1961 | 3,978 | | 1960 | 3,962 |
|