| Year | Value | | 2022 | 28,565 | | 2021 | 28,098 | | 2020 | 27,584 | | 2019 | 27,016 | | 2018 | 26,403 | | 2017 | 25,745 | | 2016 | 25,022 | | 2015 | 24,225 | | 2014 | 23,368 | | 2013 | 22,460 | | 2012 | 21,495 | | 2011 | 20,499 | | 2010 | 19,538 | | 2009 | 18,736 | | 2008 | 18,080 | | 2007 | 17,488 | | 2006 | 16,984 | | 2005 | 16,550 | | 2004 | 16,159 | | 2003 | 15,790 | | 2002 | 15,420 | | 2001 | 15,022 | | 2000 | 14,605 | | 1999 | 14,230 | | 1998 | 13,837 | | 1997 | 13,335 | | 1996 | 12,729 | | 1995 | 12,010 | | 1994 | 11,194 | | 1993 | 10,382 | | 1992 | 9,648 | | 1991 | 9,015 | | 1990 | 8,504 | | 1989 | 8,062 | | 1988 | 7,638 | | 1987 | 7,226 | | 1986 | 6,820 | | 1985 | 6,432 | | 1984 | 6,075 | | 1983 | 5,759 | | 1982 | 5,489 | | 1981 | 5,271 | | 1980 | 5,152 | | 1979 | 5,253 | | 1978 | 5,495 | | 1977 | 5,724 | | 1976 | 5,925 | | 1975 | 6,074 | | 1974 | 6,174 | | 1973 | 6,273 | | 1972 | 6,400 | | 1971 | 6,491 | | 1970 | 6,437 | | 1969 | 6,359 | | 1968 | 6,351 | | 1967 | 6,339 | | 1966 | 6,313 | | 1965 | 6,260 | | 1964 | 6,177 | | 1963 | 6,072 | | 1962 | 5,950 | | 1961 | 5,793 | | 1960 | 5,654 |
|