| Year | Value | | 2022 | 32,897 | | 2021 | 32,942 | | 2020 | 33,156 | | 2019 | 33,278 | | 2018 | 33,209 | | 2017 | 33,059 | | 2016 | 32,789 | | 2015 | 32,475 | | 2014 | 32,240 | | 2013 | 32,077 | | 2012 | 31,863 | | 2011 | 31,183 | | 2010 | 30,261 | | 2009 | 29,664 | | 2008 | 29,246 | | 2007 | 28,856 | | 2006 | 28,382 | | 2005 | 27,871 | | 2004 | 27,393 | | 2003 | 26,878 | | 2002 | 26,270 | | 2001 | 25,627 | | 2000 | 25,063 | | 1999 | 24,586 | | 1998 | 24,119 | | 1997 | 23,656 | | 1996 | 23,229 | | 1995 | 22,812 | | 1994 | 22,391 | | 1993 | 21,966 | | 1992 | 21,522 | | 1991 | 21,207 | | 1990 | 20,911 | | 1989 | 20,614 | | 1988 | 20,378 | | 1987 | 20,283 | | 1986 | 20,015 | | 1985 | 19,637 | | 1984 | 19,245 | | 1983 | 18,851 | | 1982 | 18,399 | | 1981 | 17,895 | | 1980 | 17,340 | | 1979 | 16,759 | | 1978 | 16,138 | | 1977 | 15,487 | | 1976 | 14,831 | | 1975 | 14,156 | | 1974 | 13,473 | | 1973 | 12,745 | | 1972 | 12,019 | | 1971 | 11,343 | | 1970 | 10,865 | | 1969 | 10,809 | | 1968 | 10,547 | | 1967 | 10,132 | | 1966 | 9,760 | | 1965 | 9,397 | | 1964 | 9,023 | | 1963 | 8,657 | | 1962 | 8,300 | | 1961 | 7,948 | | 1960 | 7,607 |
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