| Year | Value | | 2022 | 19,081 | | 2021 | 18,643 | | 2020 | 18,144 | | 2019 | 17,553 | | 2018 | 16,897 | | 2017 | 16,201 | | 2016 | 15,607 | | 2015 | 15,173 | | 2014 | 14,835 | | 2013 | 14,577 | | 2012 | 14,372 | | 2011 | 14,191 | | 2010 | 13,999 | | 2009 | 13,762 | | 2008 | 13,468 | | 2007 | 13,123 | | 2006 | 12,727 | | 2005 | 12,273 | | 2004 | 11,826 | | 2003 | 11,496 | | 2002 | 11,350 | | 2001 | 11,405 | | 2000 | 11,627 | | 1999 | 11,855 | | 1998 | 11,868 | | 1997 | 11,681 | | 1996 | 11,416 | | 1995 | 11,128 | | 1994 | 10,926 | | 1993 | 10,864 | | 1992 | 11,342 | | 1991 | 11,754 | | 1990 | 11,522 | | 1989 | 11,183 | | 1988 | 10,820 | | 1987 | 10,450 | | 1986 | 10,078 | | 1985 | 9,709 | | 1984 | 9,343 | | 1983 | 8,974 | | 1982 | 8,609 | | 1981 | 8,248 | | 1980 | 7,897 | | 1979 | 7,554 | | 1978 | 7,217 | | 1977 | 6,889 | | 1976 | 6,576 | | 1975 | 6,276 | | 1974 | 5,989 | | 1973 | 5,718 | | 1972 | 5,465 | | 1971 | 5,226 | | 1970 | 5,000 | | 1969 | 4,786 | | 1968 | 4,586 | | 1967 | 4,399 | | 1966 | 4,227 | | 1965 | 4,068 | | 1964 | 3,920 | | 1963 | 3,784 | | 1962 | 3,656 | | 1961 | 3,538 | | 1960 | 3,431 |
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