| Year | Value | | 2022 | 21,284,888 | | 2021 | 20,796,390 | | 2020 | 20,483,982 | | 2019 | 20,204,228 | | 2018 | 19,875,951 | | 2017 | 19,581,817 | | 2016 | 19,373,742 | | 2015 | 19,266,249 | | 2014 | 19,177,942 | | 2013 | 19,067,058 | | 2012 | 18,989,546 | | 2011 | 18,963,005 | | 2010 | 18,945,423 | | 2009 | 18,856,880 | | 2008 | 18,669,898 | | 2007 | 18,407,311 | | 2006 | 18,109,431 | | 2005 | 17,801,257 | | 2004 | 17,523,423 | | 2003 | 17,287,494 | | 2002 | 17,036,058 | | 2001 | 16,751,887 | | 2000 | 16,437,698 | | 1999 | 16,097,031 | | 1998 | 15,722,641 | | 1997 | 15,277,317 | | 1996 | 14,763,845 | | 1995 | 14,263,727 | | 1994 | 13,784,557 | | 1993 | 13,291,474 | | 1992 | 12,875,882 | | 1991 | 12,558,623 | | 1990 | 12,292,408 | | 1989 | 11,919,166 | | 1988 | 11,633,863 | | 1987 | 11,350,063 | | 1986 | 11,044,934 | | 1985 | 10,742,767 | | 1984 | 10,448,524 | | 1983 | 10,136,402 | | 1982 | 9,809,229 | | 1981 | 9,474,698 | | 1980 | 9,122,894 | | 1979 | 8,751,988 | | 1978 | 8,397,273 | | 1977 | 8,062,267 | | 1976 | 7,747,165 | | 1975 | 7,486,917 | | 1974 | 7,268,403 | | 1973 | 7,069,711 | | 1972 | 6,876,923 | | 1971 | 6,661,432 | | 1970 | 6,421,216 | | 1969 | 6,174,241 | | 1968 | 5,929,230 | | 1967 | 5,696,580 | | 1966 | 5,478,116 | | 1965 | 5,272,460 | | 1964 | 5,068,521 | | 1963 | 4,861,084 | | 1962 | 4,659,194 | | 1961 | 4,475,842 | | 1960 | 4,318,197 |
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