| Year | Value | | 2022 | 4,147 | | 2021 | 4,158 | | 2020 | 4,110 | | 2019 | 4,034 | | 2018 | 3,962 | | 2017 | 3,888 | | 2016 | 3,860 | | 2015 | 3,909 | | 2014 | 3,999 | | 2013 | 4,120 | | 2012 | 4,266 | | 2011 | 4,400 | | 2010 | 4,505 | | 2009 | 4,568 | | 2008 | 4,614 | | 2007 | 4,666 | | 2006 | 4,729 | | 2005 | 4,799 | | 2004 | 4,863 | | 2003 | 4,905 | | 2002 | 4,914 | | 2001 | 4,884 | | 2000 | 4,834 | | 1999 | 4,797 | | 1998 | 4,780 | | 1997 | 4,784 | | 1996 | 4,817 | | 1995 | 4,877 | | 1994 | 4,954 | | 1993 | 5,032 | | 1992 | 5,091 | | 1991 | 5,108 | | 1990 | 5,123 | | 1989 | 5,146 | | 1988 | 5,134 | | 1987 | 5,076 | | 1986 | 4,961 | | 1985 | 4,784 | | 1984 | 4,569 | | 1983 | 4,351 | | 1982 | 4,150 | | 1981 | 3,977 | | 1980 | 3,857 | | 1979 | 3,788 | | 1978 | 3,692 | | 1977 | 3,551 | | 1976 | 3,393 | | 1975 | 3,200 | | 1974 | 2,970 | | 1973 | 2,764 | | 1972 | 2,601 | | 1971 | 2,465 | | 1970 | 2,377 | | 1969 | 2,326 | | 1968 | 2,300 | | 1967 | 2,288 | | 1966 | 2,275 | | 1965 | 2,259 | | 1964 | 2,241 | | 1963 | 2,227 | | 1962 | 2,213 | | 1961 | 2,199 | | 1960 | 2,189 |
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