| Year | Value | | 2022 | 13,377 | | 2021 | 13,038 | | 2020 | 12,789 | | 2019 | 12,647 | | 2018 | 12,572 | | 2017 | 12,528 | | 2016 | 12,493 | | 2015 | 12,440 | | 2014 | 12,347 | | 2013 | 12,209 | | 2012 | 12,030 | | 2011 | 11,814 | | 2010 | 11,564 | | 2009 | 11,288 | | 2008 | 10,980 | | 2007 | 10,635 | | 2006 | 10,267 | | 2005 | 9,886 | | 2004 | 9,513 | | 2003 | 9,207 | | 2002 | 8,985 | | 2001 | 8,797 | | 2000 | 8,623 | | 1999 | 8,458 | | 1998 | 8,246 | | 1997 | 7,968 | | 1996 | 7,671 | | 1995 | 7,382 | | 1994 | 7,101 | | 1993 | 6,830 | | 1992 | 6,577 | | 1991 | 6,345 | | 1990 | 6,131 | | 1989 | 5,969 | | 1988 | 5,864 | | 1987 | 5,778 | | 1986 | 5,712 | | 1985 | 5,664 | | 1984 | 5,626 | | 1983 | 5,592 | | 1982 | 5,557 | | 1981 | 5,517 | | 1980 | 5,473 | | 1979 | 5,406 | | 1978 | 5,278 | | 1977 | 5,091 | | 1976 | 4,888 | | 1975 | 4,687 | | 1974 | 4,490 | | 1973 | 4,321 | | 1972 | 4,168 | | 1971 | 4,012 | | 1970 | 3,866 | | 1969 | 3,736 | | 1968 | 3,602 | | 1967 | 3,481 | | 1966 | 3,395 | | 1965 | 3,322 | | 1964 | 3,260 | | 1963 | 3,203 | | 1962 | 3,143 | | 1961 | 3,079 | | 1960 | 3,011 |
|