Year | Value | 2022 | 21,450 | 2021 | 21,307 | 2020 | 20,984 | 2019 | 20,517 | 2018 | 19,970 | 2017 | 19,428 | 2016 | 18,949 | 2015 | 18,596 | 2014 | 18,428 | 2013 | 18,448 | 2012 | 18,606 | 2011 | 18,840 | 2010 | 19,013 | 2009 | 19,023 | 2008 | 18,902 | 2007 | 18,721 | 2006 | 18,578 | 2005 | 18,552 | 2004 | 18,605 | 2003 | 18,675 | 2002 | 18,707 | 2001 | 18,618 | 2000 | 18,362 | 1999 | 17,909 | 1998 | 17,257 | 1997 | 16,421 | 1996 | 15,426 | 1995 | 14,332 | 1994 | 13,322 | 1993 | 12,544 | 1992 | 11,907 | 1991 | 11,330 | 1990 | 10,820 | 1989 | 10,324 | 1988 | 9,828 | 1987 | 9,408 | 1986 | 9,079 | 1985 | 8,812 | 1984 | 8,637 | 1983 | 8,558 | 1982 | 8,557 | 1981 | 8,610 | 1980 | 8,696 | 1979 | 8,808 | 1978 | 8,914 | 1977 | 8,998 | 1976 | 9,081 | 1975 | 9,179 | 1974 | 9,288 | 1973 | 9,387 | 1972 | 9,436 | 1971 | 9,332 | 1970 | 9,059 | 1969 | 8,726 | 1968 | 8,409 | 1967 | 8,141 | 1966 | 7,925 | 1965 | 7,745 | 1964 | 7,522 | 1963 | 7,174 | 1962 | 6,826 | 1961 | 6,566 | 1960 | 6,328 |
|