| Year | Value | | 2022 | 28,650 | | 2021 | 27,403 | | 2020 | 26,069 | | 2019 | 24,880 | | 2018 | 23,963 | | 2017 | 23,135 | | 2016 | 22,474 | | 2015 | 21,976 | | 2014 | 21,342 | | 2013 | 20,591 | | 2012 | 19,964 | | 2011 | 19,441 | | 2010 | 19,033 | | 2009 | 18,742 | | 2008 | 18,459 | | 2007 | 18,096 | | 2006 | 17,618 | | 2005 | 17,090 | | 2004 | 16,560 | | 2003 | 15,993 | | 2002 | 15,417 | | 2001 | 14,909 | | 2000 | 14,442 | | 1999 | 14,015 | | 1998 | 13,649 | | 1997 | 13,323 | | 1996 | 13,002 | | 1995 | 12,718 | | 1994 | 12,476 | | 1993 | 12,252 | | 1992 | 12,022 | | 1991 | 11,794 | | 1990 | 11,566 | | 1989 | 11,310 | | 1988 | 11,028 | | 1987 | 10,733 | | 1986 | 10,459 | | 1985 | 10,196 | | 1984 | 9,907 | | 1983 | 9,607 | | 1982 | 9,291 | | 1981 | 8,951 | | 1980 | 8,601 | | 1979 | 8,221 | | 1978 | 7,844 | | 1977 | 7,532 | | 1976 | 7,260 | | 1975 | 7,041 | | 1974 | 6,893 | | 1973 | 6,786 | | 1972 | 6,678 | | 1971 | 6,560 | | 1970 | 6,420 | | 1969 | 6,249 | | 1968 | 6,088 | | 1967 | 5,950 | | 1966 | 5,794 | | 1965 | 5,609 | | 1964 | 5,418 | | 1963 | 5,235 | | 1962 | 5,070 | | 1961 | 4,945 | | 1960 | 4,852 |
|