| Year | Value | | 2022 | 20,524,259 | | 2021 | 20,052,490 | | 2020 | 19,691,549 | | 2019 | 19,337,431 | | 2018 | 18,950,040 | | 2017 | 18,600,460 | | 2016 | 18,335,218 | | 2015 | 18,179,294 | | 2014 | 18,094,607 | | 2013 | 18,035,929 | | 2012 | 18,001,317 | | 2011 | 17,985,165 | | 2010 | 17,943,374 | | 2009 | 17,831,446 | | 2008 | 17,674,465 | | 2007 | 17,477,809 | | 2006 | 17,254,143 | | 2005 | 17,013,748 | | 2004 | 16,753,947 | | 2003 | 16,482,008 | | 2002 | 16,182,490 | | 2001 | 15,848,493 | | 2000 | 15,484,724 | | 1999 | 15,103,799 | | 1998 | 14,708,582 | | 1997 | 14,281,519 | | 1996 | 13,826,149 | | 1995 | 13,384,088 | | 1994 | 12,963,320 | | 1993 | 12,531,572 | | 1992 | 12,134,953 | | 1991 | 11,801,528 | | 1990 | 11,522,153 | | 1989 | 11,149,681 | | 1988 | 10,867,949 | | 1987 | 10,596,156 | | 1986 | 10,316,354 | | 1985 | 10,043,899 | | 1984 | 9,779,235 | | 1983 | 9,506,811 | | 1982 | 9,223,995 | | 1981 | 8,928,482 | | 1980 | 8,614,274 | | 1979 | 8,279,207 | | 1978 | 7,959,052 | | 1977 | 7,659,611 | | 1976 | 7,374,293 | | 1975 | 7,128,791 | | 1974 | 6,912,232 | | 1973 | 6,712,454 | | 1972 | 6,523,476 | | 1971 | 6,319,652 | | 1970 | 6,097,959 | | 1969 | 5,869,041 | | 1968 | 5,642,386 | | 1967 | 5,430,093 | | 1966 | 5,232,171 | | 1965 | 5,047,050 | | 1964 | 4,865,839 | | 1963 | 4,681,069 | | 1962 | 4,498,797 | | 1961 | 4,331,264 | | 1960 | 4,187,903 |
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