| Year | Value | | 2022 | 15,352 | | 2021 | 15,014 | | 2020 | 14,638 | | 2019 | 14,207 | | 2018 | 13,738 | | 2017 | 13,255 | | 2016 | 12,768 | | 2015 | 12,263 | | 2014 | 11,707 | | 2013 | 11,088 | | 2012 | 10,410 | | 2011 | 9,717 | | 2010 | 9,074 | | 2009 | 8,540 | | 2008 | 8,171 | | 2007 | 7,985 | | 2006 | 7,929 | | 2005 | 7,912 | | 2004 | 7,828 | | 2003 | 7,626 | | 2002 | 7,213 | | 2001 | 6,709 | | 2000 | 6,389 | | 1999 | 6,365 | | 1998 | 6,527 | | 1997 | 6,685 | | 1996 | 6,813 | | 1995 | 6,916 | | 1994 | 6,997 | | 1993 | 7,056 | | 1992 | 7,091 | | 1991 | 7,105 | | 1990 | 7,083 | | 1989 | 7,012 | | 1988 | 6,896 | | 1987 | 6,745 | | 1986 | 6,582 | | 1985 | 6,420 | | 1984 | 6,268 | | 1983 | 6,127 | | 1982 | 6,001 | | 1981 | 5,883 | | 1980 | 5,742 | | 1979 | 5,555 | | 1978 | 5,348 | | 1977 | 5,149 | | 1976 | 4,966 | | 1975 | 4,804 | | 1974 | 4,662 | | 1973 | 4,541 | | 1972 | 4,436 | | 1971 | 4,343 | | 1970 | 4,258 | | 1969 | 4,178 | | 1968 | 4,101 | | 1967 | 4,030 | | 1966 | 3,966 | | 1965 | 3,900 | | 1964 | 3,832 | | 1963 | 3,766 | | 1962 | 3,694 | | 1961 | 3,616 | | 1960 | 3,528 |
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