| Year | Value | | 2022 | 14,293 | | 2021 | 13,858 | | 2020 | 14,011 | | 2019 | 14,197 | | 2018 | 14,241 | | 2017 | 14,475 | | 2016 | 14,892 | | 2015 | 15,184 | | 2014 | 15,179 | | 2013 | 15,021 | | 2012 | 14,331 | | 2011 | 12,967 | | 2010 | 11,576 | | 2009 | 10,426 | | 2008 | 9,434 | | 2007 | 8,949 | | 2006 | 9,117 | | 2005 | 9,433 | | 2004 | 9,555 | | 2003 | 9,484 | | 2002 | 9,355 | | 2001 | 9,244 | | 2000 | 9,097 | | 1999 | 8,958 | | 1998 | 8,821 | | 1997 | 8,601 | | 1996 | 8,337 | | 1995 | 8,145 | | 1994 | 8,001 | | 1993 | 7,924 | | 1992 | 7,900 | | 1991 | 7,830 | | 1990 | 7,580 | | 1989 | 7,411 | | 1988 | 7,148 | | 1987 | 6,835 | | 1986 | 6,524 | | 1985 | 6,160 | | 1984 | 5,877 | | 1983 | 5,823 | | 1982 | 5,805 | | 1981 | 5,817 | | 1980 | 5,939 | | 1979 | 6,063 | | 1978 | 6,206 | | 1977 | 6,352 | | 1976 | 6,538 | | 1975 | 6,694 | | 1974 | 6,768 | | 1973 | 6,805 | | 1972 | 6,743 | | 1971 | 6,586 | | 1970 | 6,340 | | 1969 | 6,076 | | 1968 | 5,845 | | 1967 | 5,649 | | 1966 | 5,526 | | 1965 | 5,484 | | 1964 | 5,496 | | 1963 | 5,537 | | 1962 | 5,589 | | 1961 | 5,624 | | 1960 | 5,613 |
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