| Year | Value | | 2022 | 3,600 | | 2021 | 3,625 | | 2020 | 3,676 | | 2019 | 3,709 | | 2018 | 3,710 | | 2017 | 3,715 | | 2016 | 3,723 | | 2015 | 3,735 | | 2014 | 3,749 | | 2013 | 3,772 | | 2012 | 3,814 | | 2011 | 3,875 | | 2010 | 3,956 | | 2009 | 4,037 | | 2008 | 4,128 | | 2007 | 4,209 | | 2006 | 4,224 | | 2005 | 4,221 | | 2004 | 4,300 | | 2003 | 4,409 | | 2002 | 4,504 | | 2001 | 4,591 | | 2000 | 4,627 | | 1999 | 4,490 | | 1998 | 4,231 | | 1997 | 4,008 | | 1996 | 3,824 | | 1995 | 3,697 | | 1994 | 3,614 | | 1993 | 3,529 | | 1992 | 3,416 | | 1991 | 3,356 | | 1990 | 3,316 | | 1989 | 3,196 | | 1988 | 3,032 | | 1987 | 2,881 | | 1986 | 2,756 | | 1985 | 2,643 | | 1984 | 2,544 | | 1983 | 2,448 | | 1982 | 2,330 | | 1981 | 2,224 | | 1980 | 2,161 | | 1979 | 2,125 | | 1978 | 2,108 | | 1977 | 2,099 | | 1976 | 2,081 | | 1975 | 2,044 | | 1974 | 1,998 | | 1973 | 1,951 | | 1972 | 1,900 | | 1971 | 1,846 | | 1970 | 1,800 | | 1969 | 1,762 | | 1968 | 1,726 | | 1967 | 1,690 | | 1966 | 1,638 | | 1965 | 1,574 | | 1964 | 1,518 | | 1963 | 1,469 | | 1962 | 1,439 | | 1961 | 1,430 | | 1960 | 1,421 |
|