| Year | Value | | 2022 | 11,869 | | 2021 | 11,483 | | 2020 | 11,322 | | 2019 | 11,153 | | 2018 | 11,053 | | 2017 | 11,102 | | 2016 | 11,189 | | 2015 | 11,270 | | 2014 | 11,401 | | 2013 | 11,597 | | 2012 | 11,776 | | 2011 | 11,903 | | 2010 | 12,056 | | 2009 | 12,186 | | 2008 | 12,176 | | 2007 | 12,013 | | 2006 | 11,675 | | 2005 | 11,179 | | 2004 | 10,789 | | 2003 | 10,542 | | 2002 | 10,418 | | 2001 | 10,587 | | 2000 | 10,921 | | 1999 | 11,208 | | 1998 | 11,247 | | 1997 | 11,039 | | 1996 | 10,835 | | 1995 | 10,709 | | 1994 | 10,532 | | 1993 | 10,545 | | 1992 | 10,812 | | 1991 | 10,940 | | 1990 | 10,862 | | 1989 | 10,812 | | 1988 | 10,682 | | 1987 | 10,479 | | 1986 | 10,487 | | 1985 | 10,741 | | 1984 | 11,024 | | 1983 | 11,264 | | 1982 | 11,451 | | 1981 | 11,486 | | 1980 | 11,496 | | 1979 | 11,599 | | 1978 | 11,604 | | 1977 | 11,581 | | 1976 | 11,633 | | 1975 | 11,526 | | 1974 | 11,286 | | 1973 | 11,110 | | 1972 | 10,886 | | 1971 | 10,541 | | 1970 | 10,330 | | 1969 | 10,182 | | 1968 | 9,917 | | 1967 | 9,663 | | 1966 | 9,473 | | 1965 | 9,191 | | 1964 | 8,811 | | 1963 | 8,453 | | 1962 | 8,080 | | 1961 | 7,657 | | 1960 | 7,155 |
|