| Year | Value | | 2022 | 3,135 | | 2021 | 3,122 | | 2020 | 3,109 | | 2019 | 3,095 | | 2018 | 3,093 | | 2017 | 3,107 | | 2016 | 3,136 | | 2015 | 3,193 | | 2014 | 3,270 | | 2013 | 3,345 | | 2012 | 3,415 | | 2011 | 3,472 | | 2010 | 3,498 | | 2009 | 3,486 | | 2008 | 3,443 | | 2007 | 3,369 | | 2006 | 3,256 | | 2005 | 3,104 | | 2004 | 2,936 | | 2003 | 2,764 | | 2002 | 2,587 | | 2001 | 2,433 | | 2000 | 2,331 | | 1999 | 2,251 | | 1998 | 2,163 | | 1997 | 2,067 | | 1996 | 1,975 | | 1995 | 1,885 | | 1994 | 1,801 | | 1993 | 1,727 | | 1992 | 1,667 | | 1991 | 1,614 | | 1990 | 1,577 | | 1989 | 1,562 | | 1988 | 1,566 | | 1987 | 1,588 | | 1986 | 1,612 | | 1985 | 1,632 | | 1984 | 1,653 | | 1983 | 1,674 | | 1982 | 1,691 | | 1981 | 1,717 | | 1980 | 1,758 | | 1979 | 1,805 | | 1978 | 1,850 | | 1977 | 1,886 | | 1976 | 1,909 | | 1975 | 1,917 | | 1974 | 1,917 | | 1973 | 1,913 | | 1972 | 1,905 | | 1971 | 1,897 | | 1970 | 1,893 | | 1969 | 1,897 | | 1968 | 1,899 | | 1967 | 1,899 | | 1966 | 1,896 | | 1965 | 1,894 | | 1964 | 1,895 | | 1963 | 1,902 | | 1962 | 1,917 | | 1961 | 1,941 | | 1960 | 1,958 |
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