| Year | Value | | 2022 | 3,224 | | 2021 | 3,260 | | 2020 | 3,346 | | 2019 | 3,421 | | 2018 | 3,458 | | 2017 | 3,521 | | 2016 | 3,593 | | 2015 | 3,632 | | 2014 | 3,668 | | 2013 | 3,699 | | 2012 | 3,679 | | 2011 | 3,611 | | 2010 | 3,534 | | 2009 | 3,481 | | 2008 | 3,436 | | 2007 | 3,389 | | 2006 | 3,349 | | 2005 | 3,292 | | 2004 | 3,228 | | 2003 | 3,186 | | 2002 | 3,141 | | 2001 | 3,088 | | 2000 | 3,060 | | 1999 | 3,036 | | 1998 | 2,988 | | 1997 | 2,953 | | 1996 | 2,956 | | 1995 | 2,953 | | 1994 | 2,927 | | 1993 | 2,914 | | 1992 | 2,906 | | 1991 | 2,890 | | 1990 | 2,928 | | 1989 | 3,052 | | 1988 | 3,213 | | 1987 | 3,385 | | 1986 | 3,572 | | 1985 | 3,781 | | 1984 | 3,952 | | 1983 | 4,050 | | 1982 | 4,122 | | 1981 | 4,191 | | 1980 | 4,247 | | 1979 | 4,283 | | 1978 | 4,292 | | 1977 | 4,272 | | 1976 | 4,221 | | 1975 | 4,137 | | 1974 | 4,028 | | 1973 | 3,908 | | 1972 | 3,783 | | 1971 | 3,652 | | 1970 | 3,514 | | 1969 | 3,358 | | 1968 | 3,213 | | 1967 | 3,109 | | 1966 | 3,033 | | 1965 | 2,982 | | 1964 | 2,983 | | 1963 | 3,010 | | 1962 | 3,021 | | 1961 | 3,028 | | 1960 | 3,014 |
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