| Year | Value | | 2022 | 16,510 | | 2021 | 16,237 | | 2020 | 15,874 | | 2019 | 15,390 | | 2018 | 14,828 | | 2017 | 14,257 | | 2016 | 13,761 | | 2015 | 13,375 | | 2014 | 13,067 | | 2013 | 12,813 | | 2012 | 12,590 | | 2011 | 12,385 | | 2010 | 12,172 | | 2009 | 11,917 | | 2008 | 11,606 | | 2007 | 11,241 | | 2006 | 10,841 | | 2005 | 10,425 | | 2004 | 10,044 | | 2003 | 9,748 | | 2002 | 9,578 | | 2001 | 9,548 | | 2000 | 9,637 | | 1999 | 9,723 | | 1998 | 9,665 | | 1997 | 9,465 | | 1996 | 9,193 | | 1995 | 8,912 | | 1994 | 8,707 | | 1993 | 8,624 | | 1992 | 8,980 | | 1991 | 9,290 | | 1990 | 9,096 | | 1989 | 8,825 | | 1988 | 8,542 | | 1987 | 8,257 | | 1986 | 7,976 | | 1985 | 7,705 | | 1984 | 7,440 | | 1983 | 7,179 | | 1982 | 6,922 | | 1981 | 6,671 | | 1980 | 6,424 | | 1979 | 6,185 | | 1978 | 5,952 | | 1977 | 5,729 | | 1976 | 5,513 | | 1975 | 5,310 | | 1974 | 5,118 | | 1973 | 4,934 | | 1972 | 4,758 | | 1971 | 4,593 | | 1970 | 4,432 | | 1969 | 4,281 | | 1968 | 4,140 | | 1967 | 4,006 | | 1966 | 3,878 | | 1965 | 3,759 | | 1964 | 3,647 | | 1963 | 3,542 | | 1962 | 3,441 | | 1961 | 3,347 | | 1960 | 3,261 |
|