| Year | Value | | 2022 | 18,244 | | 2021 | 18,153 | | 2020 | 18,054 | | 2019 | 17,946 | | 2018 | 17,813 | | 2017 | 17,638 | | 2016 | 17,421 | | 2015 | 17,193 | | 2014 | 16,974 | | 2013 | 16,776 | | 2012 | 16,617 | | 2011 | 16,482 | | 2010 | 16,198 | | 2009 | 15,759 | | 2008 | 15,308 | | 2007 | 14,840 | | 2006 | 14,359 | | 2005 | 13,877 | | 2004 | 13,418 | | 2003 | 13,022 | | 2002 | 12,712 | | 2001 | 12,488 | | 2000 | 12,329 | | 1999 | 12,200 | | 1998 | 12,052 | | 1997 | 11,846 | | 1996 | 11,570 | | 1995 | 11,218 | | 1994 | 10,806 | | 1993 | 10,344 | | 1992 | 9,836 | | 1991 | 9,247 | | 1990 | 8,578 | | 1989 | 7,909 | | 1988 | 7,292 | | 1987 | 6,718 | | 1986 | 6,172 | | 1985 | 5,652 | | 1984 | 5,156 | | 1983 | 4,713 | | 1982 | 4,371 | | 1981 | 4,141 | | 1980 | 4,005 | | 1979 | 3,925 | | 1978 | 3,847 | | 1977 | 3,754 | | 1976 | 3,653 | | 1975 | 3,556 | | 1974 | 3,476 | | 1973 | 3,418 | | 1972 | 3,371 | | 1971 | 3,300 | | 1970 | 3,183 | | 1969 | 3,034 | | 1968 | 2,872 | | 1967 | 2,705 | | 1966 | 2,555 | | 1965 | 2,429 | | 1964 | 2,327 | | 1963 | 2,242 | | 1962 | 2,168 | | 1961 | 2,104 | | 1960 | 2,034 |
|