| Year | Value | | 2022 | 3,307 | | 2021 | 3,406 | | 2020 | 3,482 | | 2019 | 3,522 | | 2018 | 3,520 | | 2017 | 3,501 | | 2016 | 3,479 | | 2015 | 3,462 | | 2014 | 3,457 | | 2013 | 3,467 | | 2012 | 3,498 | | 2011 | 3,542 | | 2010 | 3,598 | | 2009 | 3,673 | | 2008 | 3,758 | | 2007 | 3,826 | | 2006 | 3,879 | | 2005 | 3,939 | | 2004 | 4,014 | | 2003 | 4,105 | | 2002 | 4,194 | | 2001 | 4,267 | | 2000 | 4,291 | | 1999 | 4,281 | | 1998 | 4,246 | | 1997 | 4,163 | | 1996 | 4,130 | | 1995 | 4,171 | | 1994 | 4,159 | | 1993 | 4,108 | | 1992 | 4,078 | | 1991 | 4,024 | | 1990 | 3,993 | | 1989 | 3,953 | | 1988 | 4,016 | | 1987 | 4,072 | | 1986 | 4,160 | | 1985 | 4,254 | | 1984 | 4,299 | | 1983 | 4,307 | | 1982 | 4,266 | | 1981 | 4,115 | | 1980 | 3,936 | | 1979 | 3,685 | | 1978 | 3,559 | | 1977 | 3,340 | | 1976 | 3,344 | | 1975 | 3,177 | | 1974 | 2,927 | | 1973 | 2,676 | | 1972 | 2,398 | | 1971 | 2,219 | | 1970 | 1,978 | | 1969 | 1,877 | | 1968 | 1,747 | | 1967 | 1,565 | | 1966 | 1,506 | | 1965 | 1,458 | | 1964 | 1,388 | | 1963 | 1,351 | | 1962 | 1,191 | | 1961 | 1,172 | | 1960 | 1,036 |
|