| Year | Value | | 2022 | 34,950 | | 2021 | 37,019 | | 2020 | 38,414 | | 2019 | 38,360 | | 2018 | 37,313 | | 2017 | 35,995 | | 2016 | 34,591 | | 2015 | 33,163 | | 2014 | 30,996 | | 2013 | 27,166 | | 2012 | 23,838 | | 2011 | 22,215 | | 2010 | 20,938 | | 2009 | 19,656 | | 2008 | 18,280 | | 2007 | 16,907 | | 2006 | 15,603 | | 2005 | 14,428 | | 2004 | 13,357 | | 2003 | 12,356 | | 2002 | 11,528 | | 2001 | 10,907 | | 2000 | 10,462 | | 1999 | 10,218 | | 1998 | 10,218 | | 1997 | 10,369 | | 1996 | 10,460 | | 1995 | 10,400 | | 1994 | 10,216 | | 1993 | 9,888 | | 1992 | 9,415 | | 1991 | 8,907 | | 1990 | 8,508 | | 1989 | 8,211 | | 1988 | 7,974 | | 1987 | 7,815 | | 1986 | 7,627 | | 1985 | 7,436 | | 1984 | 7,305 | | 1983 | 7,210 | | 1982 | 7,318 | | 1981 | 7,447 | | 1980 | 7,432 | | 1979 | 7,455 | | 1978 | 8,471 | | 1977 | 9,516 | | 1976 | 8,921 | | 1975 | 8,288 | | 1974 | 8,258 | | 1973 | 8,135 | | 1972 | 7,989 | | 1971 | 7,864 | | 1970 | 7,787 | | 1969 | 7,750 | | 1968 | 7,740 | | 1967 | 7,767 | | 1966 | 7,795 | | 1965 | 7,795 | | 1964 | 7,768 | | 1963 | 7,697 | | 1962 | 7,586 | | 1961 | 7,452 | | 1960 | 7,320 |
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