| Year | Value | | 2022 | 22,826 | | 2021 | 23,310 | | 2020 | 23,363 | | 2019 | 23,136 | | 2018 | 22,805 | | 2017 | 22,512 | | 2016 | 22,473 | | 2015 | 22,661 | | 2014 | 22,779 | | 2013 | 22,383 | | 2012 | 21,326 | | 2011 | 19,779 | | 2010 | 17,963 | | 2009 | 16,438 | | 2008 | 15,379 | | 2007 | 14,506 | | 2006 | 13,653 | | 2005 | 12,639 | | 2004 | 11,308 | | 2003 | 9,820 | | 2002 | 8,440 | | 2001 | 7,283 | | 2000 | 6,377 | | 1999 | 5,751 | | 1998 | 5,431 | | 1997 | 5,328 | | 1996 | 5,281 | | 1995 | 5,229 | | 1994 | 5,177 | | 1993 | 5,104 | | 1992 | 5,040 | | 1991 | 5,017 | | 1990 | 4,990 | | 1989 | 4,971 | | 1988 | 5,014 | | 1987 | 5,056 | | 1986 | 5,039 | | 1985 | 4,973 | | 1984 | 4,857 | | 1983 | 4,681 | | 1982 | 4,493 | | 1981 | 4,367 | | 1980 | 4,364 | | 1979 | 4,442 | | 1978 | 4,501 | | 1977 | 4,507 | | 1976 | 4,458 | | 1975 | 4,370 | | 1974 | 4,270 | | 1973 | 4,185 | | 1972 | 4,129 | | 1971 | 4,090 | | 1970 | 4,030 | | 1969 | 3,930 | | 1968 | 3,811 | | 1967 | 3,678 | | 1966 | 3,524 | | 1965 | 3,350 | | 1964 | 3,221 | | 1963 | 3,119 | | 1962 | 2,995 | | 1961 | 2,851 | | 1960 | 2,873 |
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