| Year | Value | | 2022 | 19,115 | | 2021 | 18,937 | | 2020 | 18,615 | | 2019 | 18,141 | | 2018 | 17,573 | | 2017 | 16,971 | | 2016 | 16,355 | | 2015 | 15,719 | | 2014 | 15,076 | | 2013 | 14,420 | | 2012 | 13,763 | | 2011 | 13,043 | | 2010 | 12,326 | | 2009 | 11,708 | | 2008 | 11,113 | | 2007 | 10,460 | | 2006 | 9,745 | | 2005 | 9,015 | | 2004 | 8,429 | | 2003 | 8,163 | | 2002 | 7,944 | | 2001 | 7,577 | | 2000 | 7,196 | | 1999 | 6,772 | | 1998 | 6,239 | | 1997 | 5,475 | | 1996 | 4,927 | | 1995 | 4,691 | | 1994 | 4,575 | | 1993 | 4,538 | | 1992 | 4,314 | | 1991 | 4,021 | | 1990 | 4,484 | | 1989 | 4,981 | | 1988 | 4,732 | | 1987 | 4,470 | | 1986 | 4,210 | | 1985 | 3,966 | | 1984 | 3,737 | | 1983 | 3,673 | | 1982 | 3,647 | | 1981 | 3,527 | | 1980 | 3,459 | | 1979 | 3,439 | | 1978 | 3,460 | | 1977 | 3,506 | | 1976 | 3,566 | | 1975 | 3,638 | | 1974 | 3,629 | | 1973 | 3,531 | | 1972 | 3,432 | | 1971 | 3,334 | | 1970 | 3,243 | | 1969 | 3,152 | | 1968 | 3,058 | | 1967 | 2,967 | | 1966 | 2,882 | | 1965 | 2,806 | | 1964 | 2,735 | | 1963 | 2,672 | | 1962 | 2,624 | | 1961 | 2,584 | | 1960 | 2,544 |
|