| Year | Value | | 2022 | 30,258 | | 2021 | 29,632 | | 2020 | 29,073 | | 2019 | 28,258 | | 2018 | 27,368 | | 2017 | 26,687 | | 2016 | 25,997 | | 2015 | 25,313 | | 2014 | 24,654 | | 2013 | 23,830 | | 2012 | 22,952 | | 2011 | 22,473 | | 2010 | 22,203 | | 2009 | 21,788 | | 2008 | 21,419 | | 2007 | 21,039 | | 2006 | 20,644 | | 2005 | 20,228 | | 2004 | 19,718 | | 2003 | 19,153 | | 2002 | 18,562 | | 2001 | 17,964 | | 2000 | 17,343 | | 1999 | 16,741 | | 1998 | 16,148 | | 1997 | 15,559 | | 1996 | 15,073 | | 1995 | 14,553 | | 1994 | 14,049 | | 1993 | 13,375 | | 1992 | 13,461 | | 1991 | 15,189 | | 1990 | 16,474 | | 1989 | 16,742 | | 1988 | 17,267 | | 1987 | 17,416 | | 1986 | 16,845 | | 1985 | 16,206 | | 1984 | 15,611 | | 1983 | 15,109 | | 1982 | 14,694 | | 1981 | 14,693 | | 1980 | 14,604 | | 1979 | 13,403 | | 1978 | 11,823 | | 1977 | 10,981 | | 1976 | 10,677 | | 1975 | 10,422 | | 1974 | 10,179 | | 1973 | 9,908 | | 1972 | 9,605 | | 1971 | 9,294 | | 1970 | 8,966 | | 1969 | 8,619 | | 1968 | 8,252 | | 1967 | 7,873 | | 1966 | 7,503 | | 1965 | 7,157 | | 1964 | 6,833 | | 1963 | 6,533 | | 1962 | 6,255 | | 1961 | 5,983 | | 1960 | 5,704 |
|