| Year | Value | | 2022 | 18,908,509 | | 2021 | 18,863,288 | | 2020 | 18,916,509 | | 2019 | 18,877,550 | | 2018 | 18,648,048 | | 2017 | 18,362,348 | | 2016 | 18,058,400 | | 2015 | 17,767,630 | | 2014 | 17,517,683 | | 2013 | 17,240,306 | | 2012 | 16,889,543 | | 2011 | 16,497,195 | | 2010 | 16,033,295 | | 2009 | 15,408,985 | | 2008 | 14,690,172 | | 2007 | 13,975,194 | | 2006 | 13,299,190 | | 2005 | 12,731,516 | | 2004 | 12,283,586 | | 2003 | 11,885,783 | | 2002 | 11,489,436 | | 2001 | 11,111,643 | | 2000 | 10,750,620 | | 1999 | 10,397,696 | | 1998 | 10,055,290 | | 1997 | 9,728,964 | | 1996 | 9,415,711 | | 1995 | 9,094,619 | | 1994 | 8,763,455 | | 1993 | 8,435,595 | | 1992 | 8,124,378 | | 1991 | 7,844,241 | | 1990 | 7,626,295 | | 1989 | 7,367,273 | | 1988 | 7,142,898 | | 1987 | 6,918,226 | | 1986 | 6,657,889 | | 1985 | 6,376,294 | | 1984 | 6,099,652 | | 1983 | 5,835,805 | | 1982 | 5,582,596 | | 1981 | 5,337,280 | | 1980 | 5,087,223 | | 1979 | 4,817,126 | | 1978 | 4,550,232 | | 1977 | 4,302,691 | | 1976 | 4,076,500 | | 1975 | 3,895,281 | | 1974 | 3,760,432 | | 1973 | 3,664,047 | | 1972 | 3,604,362 | | 1971 | 3,565,975 | | 1970 | 3,534,417 | | 1969 | 3,503,626 | | 1968 | 3,471,337 | | 1967 | 3,434,661 | | 1966 | 3,394,544 | | 1965 | 3,348,553 | | 1964 | 3,292,902 | | 1963 | 3,228,798 | | 1962 | 3,159,926 | | 1961 | 3,088,395 | | 1960 | 3,019,983 |
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