| Year | Value | | 2022 | 25,281 | | 2021 | 24,668 | | 2020 | 24,279 | | 2019 | 24,065 | | 2018 | 23,916 | | 2017 | 23,744 | | 2016 | 23,386 | | 2015 | 22,681 | | 2014 | 21,573 | | 2013 | 20,171 | | 2012 | 18,679 | | 2011 | 17,332 | | 2010 | 16,405 | | 2009 | 15,962 | | 2008 | 15,782 | | 2007 | 15,623 | | 2006 | 15,304 | | 2005 | 14,745 | | 2004 | 14,001 | | 2003 | 13,114 | | 2002 | 12,194 | | 2001 | 11,408 | | 2000 | 10,749 | | 1999 | 10,104 | | 1998 | 9,560 | | 1997 | 9,167 | | 1996 | 8,796 | | 1995 | 8,439 | | 1994 | 8,113 | | 1993 | 7,812 | | 1992 | 7,534 | | 1991 | 7,289 | | 1990 | 7,073 | | 1989 | 6,880 | | 1988 | 6,706 | | 1987 | 6,544 | | 1986 | 6,381 | | 1985 | 6,198 | | 1984 | 5,987 | | 1983 | 5,757 | | 1982 | 5,484 | | 1981 | 5,202 | | 1980 | 4,995 | | 1979 | 4,889 | | 1978 | 4,878 | | 1977 | 4,936 | | 1976 | 5,073 | | 1975 | 5,259 | | 1974 | 5,442 | | 1973 | 5,632 | | 1972 | 5,822 | | 1971 | 5,995 | | 1970 | 6,129 | | 1969 | 6,193 | | 1968 | 6,142 | | 1967 | 6,020 | | 1966 | 5,902 | | 1965 | 5,798 | | 1964 | 5,709 | | 1963 | 5,630 | | 1962 | 5,561 | | 1961 | 5,494 | | 1960 | 5,427 |
|