| Year | Value | | 2022 | 28,229 | | 2021 | 27,356 | | 2020 | 26,674 | | 2019 | 26,138 | | 2018 | 25,693 | | 2017 | 25,258 | | 2016 | 24,755 | | 2015 | 24,134 | | 2014 | 23,408 | | 2013 | 22,634 | | 2012 | 21,868 | | 2011 | 21,160 | | 2010 | 20,492 | | 2009 | 19,801 | | 2008 | 19,053 | | 2007 | 18,246 | | 2006 | 17,421 | | 2005 | 16,641 | | 2004 | 15,948 | | 2003 | 15,366 | | 2002 | 14,898 | | 2001 | 14,504 | | 2000 | 14,121 | | 1999 | 13,722 | | 1998 | 13,326 | | 1997 | 12,970 | | 1996 | 12,682 | | 1995 | 12,467 | | 1994 | 12,316 | | 1993 | 12,202 | | 1992 | 12,050 | | 1991 | 11,819 | | 1990 | 11,546 | | 1989 | 11,265 | | 1988 | 11,012 | | 1987 | 10,813 | | 1986 | 10,677 | | 1985 | 10,606 | | 1984 | 10,591 | | 1983 | 10,619 | | 1982 | 10,659 | | 1981 | 10,659 | | 1980 | 10,614 | | 1979 | 10,541 | | 1978 | 10,429 | | 1977 | 10,268 | | 1976 | 10,071 | | 1975 | 9,952 | | 1974 | 10,041 | | 1973 | 10,183 | | 1972 | 10,163 | | 1971 | 10,032 | | 1970 | 9,871 | | 1969 | 9,681 | | 1968 | 9,453 | | 1967 | 9,169 | | 1966 | 8,811 | | 1965 | 8,366 | | 1964 | 7,839 | | 1963 | 7,260 | | 1962 | 6,685 | | 1961 | 6,213 | | 1960 | 5,988 |
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