| Year | Value | | 2022 | 5,536 | | 2021 | 5,464 | | 2020 | 5,358 | | 2019 | 5,266 | | 2018 | 5,195 | | 2017 | 5,108 | | 2016 | 5,025 | | 2015 | 4,968 | | 2014 | 4,954 | | 2013 | 4,991 | | 2012 | 5,080 | | 2011 | 5,214 | | 2010 | 5,383 | | 2009 | 5,566 | | 2008 | 5,760 | | 2007 | 5,966 | | 2006 | 6,181 | | 2005 | 6,397 | | 2004 | 6,603 | | 2003 | 6,791 | | 2002 | 6,937 | | 2001 | 7,035 | | 2000 | 7,117 | | 1999 | 7,213 | | 1998 | 7,291 | | 1997 | 7,332 | | 1996 | 7,341 | | 1995 | 7,305 | | 1994 | 7,218 | | 1993 | 7,093 | | 1992 | 6,952 | | 1991 | 6,813 | | 1990 | 6,656 | | 1989 | 6,429 | | 1988 | 6,175 | | 1987 | 5,959 | | 1986 | 5,781 | | 1985 | 5,662 | | 1984 | 5,604 | | 1983 | 5,534 | | 1982 | 5,446 | | 1981 | 5,362 | | 1980 | 5,187 | | 1979 | 4,940 | | 1978 | 4,728 | | 1977 | 4,464 | | 1976 | 4,110 | | 1975 | 3,770 | | 1974 | 3,518 | | 1973 | 3,379 | | 1972 | 3,377 | | 1971 | 3,497 | | 1970 | 3,658 | | 1969 | 3,723 | | 1968 | 3,690 | | 1967 | 3,676 | | 1966 | 3,744 | | 1965 | 3,950 | | 1964 | 4,330 | | 1963 | 4,867 | | 1962 | 5,491 | | 1961 | 6,094 | | 1960 | 6,537 |
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